diff --git a/du3/program.c b/du3/program.c
new file mode 100644
index 0000000..849ad63
--- /dev/null
+++ b/du3/program.c
@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+int main() {
+    char riadok[100];
+
+    while (fgets(riadok, sizeof(riadok), stdin)) {
+
+        // prázdny riadok -> KONIEC
+        if (riadok[0] == '\n') {
+            break;
+        }
+
+        char *r = riadok;
+        char *end;
+
+        // preskoč medzery
+        while (*r == ' '){
+            r++;
+        }
+
+        // 1. číslo
+        float a = strtof(r, &end);
+        if (r == end) {
+            printf("CHYBA\n");
+            continue;
+        }
+        r = end;
+
+        while (*r == ' '){
+            r++;
+        }
+
+        // operátor
+        char or = *r;
+        if (!(or == '+' || or == '-' || or == '*' || or == '/')) {
+            printf("CHYBA\n");
+            continue;
+        }
+        r++;
+
+        while (*r == ' '){
+            r++;
+        }
+
+        // 2. číslo
+        float b = strtof(r, &end);
+        if (r == end) {
+            printf("CHYBA\n");
+            continue;
+        }
+        r = end;
+
+        while (*r == ' '){
+            r++;
+        }
+
+        // '='
+        if (*r != '=') {
+            printf("CHYBA\n");
+            continue;
+        }
+        r++;
+
+        while (*r == ' '){
+            r++;
+        }
+
+        // výsledok
+        float c = strtof(r, &end);
+        if (r == end) {
+            printf("CHYBA\n");
+            continue;
+        }
+        r = end;
+
+        // výpočet
+        float cislo;
+
+        if (or == '+') cislo = a + b;
+        else if (or == '-') cislo = a - b;
+        else if (or == '*') cislo = a * b;
+        else {
+            if (b == 0) {
+                printf("CHYBA\n");
+                continue;
+            }
+            cislo = a / b;
+        }
+
+        // porovnanie s toleranciou
+        if (fabs(cislo - c) <= 0.001) {
+            printf("OK\n");
+        } else {
+            printf("ZLE\n");
+        }
+    }
+
+    return 0;
+}
\ No newline at end of file