diff --git a/du3/program.c b/du3/program.c
new file mode 100644
index 0000000..a7f0554
--- /dev/null
+++ b/du3/program.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#define MAX_LEN 100
+
+const char* evaluate_expression(char *expression){
+    double num1, num2, result, computed_result;
+    char op;
+    
+    if(sscanf(expression, " %lf %c %lf = %lf ", &num1, &op, &num2, &result) != 4) return "CHYBA";
+    
+    switch(op){
+        case '+': computed_result = num1 + num2; break;
+        case '-': computed_result = num1 - num2; break;
+        case '*': computed_result = num1 * num2; break;
+        case '/': if (num2 == 0) return "CHYBA"; computed_result = num1 / num2; break;
+        default: return "CHYBA";
+    }
+    
+    return (round(computed_result * 100) / 100 == round(result * 100) / 100) ? "OK" : "ZLE";
+}
+
+int main(){
+    char line[MAX_LEN];
+    while(fgets(line, sizeof(line), stdin) && line[0] != '\n'){
+        printf("%s\n", evaluate_expression(line));
+    }
+    return 0;
+}