diff --git a/du3/program.c b/du3/program.c
new file mode 100644
index 0000000..8a953af
--- /dev/null
+++ b/du3/program.c
@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+#define MAX 256
+
+double zaokruhlenie_vysledku(double x) {
+    return round(x * 100.0) / 100.0;
+}
+
+double vykonaj_operaciu(double a, char op, double b) {
+    if (op == '+') return a + b;
+    if (op == '-') return a - b;
+    if (op == '*') return a * b;
+    if (op == '/') return a / b;
+    return 0;
+}
+
+int main() {
+    char riadok[MAX];
+
+    while (1) {
+        if (fgets(riadok, MAX, stdin) == NULL)
+            break;
+        if (strcmp(riadok, "\n") == 0)
+            break;
+
+        double cislo1, cislo2, vysledok;
+        char operacia;
+        int nacitane = sscanf(riadok, "%lf %c %lf = %lf", &cislo1, &operacia, &cislo2, &vysledok);
+
+        if (nacitane != 4) {
+            printf("CHYBA\n");
+            continue;
+        }
+        if (!(operacia == '+' || operacia == '-' || operacia == '*' || operacia == '/')) {
+            printf("CHYBA\n");
+            continue;
+        }
+        if (operacia == '/' && cislo2 == 0) {
+            printf("CHYBA\n");
+            continue;
+        }
+        double spravnyVysledok = vykonaj_operaciu(cislo1, operacia, cislo2);
+
+        if (zaokruhlenie_vysledku(spravnyVysledok) == zaokruhlenie_vysledku(vysledok)) {
+            printf("OK\n");
+        } else {
+            printf("ZLE\n");
+        }
+    }
+    return 0;
+}
\ No newline at end of file