diff --git a/a1/program.c b/a1/program.c
index 503e20d..fb31fa0 100644
--- a/a1/program.c
+++ b/a1/program.c
@@ -1,5 +1,262 @@
+key, [3/31/2022 11:20 AM]
 #include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
 
 int main(){
-	return 0;
-}
+  char riadok[499][499];
+  int i, o , need = 0;
+  bool first;
+  while (1){
+    o = 0;
+    while (1){
+      riadok[i][o] = getchar();
+      if (riadok[i][o] == '\n'){
+        first = true;
+        need++;
+        break;
+      }
+      o++;
+    }
+    if (first == true && riadok[i][0] == '\n'){
+      break;
+    }
+    i++;
+  }
+  for (int j = 0; j < need - 1; j++){
+    for (int g = 0; g < strlen(riadok[j]); g++){
+      if (riadok[j][g] != '.' && riadok[j][g] != '1' && riadok[j][g] != '2' && riadok[j][g] != '3' && riadok[j][g] != '4' && riadok[j][g] != '5' && riadok[j][g] != '6' && riadok[j][g] != '7' && riadok[j][g] != '8' && riadok[j][g] != '9' && riadok[j][g] != '0' && riadok[j][g] != '\n' && riadok[j][g] != '\0'){
+        riadok[j][0] = '9';
+        riadok[j][1] = '.';
+        riadok[j][2] = '9';
+        riadok[j][3] = '.';
+        riadok[j][4] = '9';
+        riadok[j][5] = '.';
+        riadok[j][6] = '\0';
+        break;
+      }
+    }
+  }
+  i = 0;
+  for (int j = 0; j < need - 1; j++){
+    i = 1;
+    for (int g = 0; g < strlen(riadok[j]); g++){
+      if ((riadok[j][g] == '1'  riadok[j][g] == '2'  riadok[j][g] == '3'  riadok[j][g] == '4'  riadok[j][g] == '5'  riadok[j][g] == '6'  riadok[j][g] == '7'  riadok[j][g] == '8'  riadok[j][g] == '9'  riadok[j][g] == '0'  riadok[j][g] == '\0')){
+        i++;
+        if (strlen(riadok[j]) == i){
+          riadok[j][0] = '9';
+          riadok[j][1] = '.';
+          riadok[j][2] = '9';
+          riadok[j][3] = '.';
+          riadok[j][4] = '9';
+          riadok[j][5] = '.';
+          riadok[j][6] = '\0';
+          break;
+        }
+      }
+    }
+  }
+  for (int j = 0; j < need - 1; j++){
+    if (riadok[j][0] == '0'){
+      riadok[j][0] = '9';
+      riadok[j][1] = '.';
+      riadok[j][2] = '9';
+      riadok[j][3] = '.';
+      riadok[j][4] = '9';
+      riadok[j][5] = '.';
+      riadok[j][6] = '\0';
+    }
+  }
+  for (int j = 0; j < need - 1; j++){
+    for (int g = 0; g < strlen(riadok[j]); g++){
+      if (riadok[j][g] == '0' && riadok[j][g - 1] == '.'){
+        riadok[j][0] = '9';
+        riadok[j][1] = '.';
+        riadok[j][2] = '9';
+        riadok[j][3] = '.';
+        riadok[j][4] = '9';
+        riadok[j][5] = '.';
+        riadok[j][6] = '\0';
+      }
+    }
+  }
+  char riadok1[499];
+  i = 0;
+  for (int j = 0; j < need - 1; j++){
+    for (int g = 0; g < strlen(riadok[j]); g++){
+      if (riadok[j][g] == '\n'){
+        riadok[j][g] = '.';
+      }
+      if (riadok[j][g] != '\0'){
+        riadok1[i] = riadok[j][g];
+        i++;
+      }
+    }
+  }
+  riadok1[i] = '\0';
+  int len = strlen(riadok1);
+  int s = 0;
+  for (int j = 0; j < len; j++){
+    if (riadok1[j] == '.'){
+      s++;
+    }
+  }
+key, [3/31/2022 11:20 AM]
+  char *endptr = NULL;
+  char *start = riadok1;
+  int number[s];
+  i = 0;
+  while (start < (riadok1 + len)){
+    number[i] = strtol(start, &endptr, 10);
+    if (number[i])
+      start = endptr + 1;
+    else
+      break;
+    i++;
+  }
+  need = 0;
+  for (int j = 0; j < s; j = j + 3){
+    if (number[j + 1] > 12  number[j + 1] < 0  number[j] < 1  number[j] > 31  number[j + 2] < 1900  number[j + 2] > 2100){
+      number[j] = 0;
+      number[j + 1] = 0;
+      number[j + 2] = 0;
+      need++;
+    }
+  }
+  for (int j = 0; j < s; j = j + 3){
+    if (number[j + 1] == 2 && number[j] == 29 && number[j + 2] % 4 != 0) {
+      number[j] = 0;
+      number[j + 1] = 0;
+      number[j + 2] = 0;
+      need++;
+    }
+  }
+  for (int j = 0; j < s; j = j + 3){
+    if (number[j + 1] == 1 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24)
+        number[j] = number[j] + 7;
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 2 && number[j] > 0 && number[j] <= 28 && number[j + 2] % 4 != 0){
+      if (number[j] <= 21){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 21){
+        number[j] = number[j] + 7 - 28;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 2 && number[j] > 0 && number[j] <= 29 && number[j + 2] % 4 == 0){
+      if (number[j] <= 22){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 22){
+        number[j] = number[j] + 7 - 29;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 3 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+key, [3/31/2022 11:20 AM]
+number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 4 && number[j] > 0 && number[j] <= 30){
+      if (number[j] <= 23){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 23){
+        number[j] = number[j] + 7 - 30;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 5 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 6 && number[j] > 0 && number[j] <= 30){
+      if (number[j] <= 23){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 23){
+        number[j] = number[j] + 7 - 30;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 7 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+
+        number[j] = number[j] + 7 - 31;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 8 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 9 && number[j] > 0 && number[j] <= 30){
+      if (number[j] <= 23){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 23){
+        number[j] = number[j] + 7 - 30;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 10 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 11 && number[j] > 0 && number[j] <= 30){
+      if (number[j] <= 23){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 23){
+        number[j] = number[j] + 7 - 30;
+        number[j + 1]++;
+      }
+    }
+    else if (number[j + 1] == 12 && number[j] > 0 && number[j] <= 31){
+      if (number[j] <= 24){
+        number[j] = number[j] + 7;
+      }
+      else if (number[j] > 24){
+        number[j] = number[j] + 7 - 31;
+        number[j + 1] = 1;
+        number[j + 2]++;
+      }
+    }
+    if (number[j] != 0 && number[j + 1] != 0 && number[j + 2] != 0){
+      printf("%d.%d.%d\n\n", number[j], number[j + 1], number[j + 2]);
+    }
+    else if (number[j] == 0 && number[j + 1] == 0 && number[j + 2] == 0){
+      puts("Neplatny datum.");
+    }
+  }
+}
\ No newline at end of file