Language: C

Source code:

#include <stdio.h> int get_char_code_at_position(char * string, int position) { return (int) (string[position - 1]); } int main() { char input[256]; printf("Enter flag to check: "); scanf("%s", input); if (strlen(input) * 4 != get_char_code_at_position(input, 1)) { printf("Wrong length!\n"); return 0; } if (strncmp(input, "4_points", 8)) { printf("Wrong check 1!\n"); return 0; } if (strcmp(&input[8], "komne") != 0) { printf("Wrong check 2!\n"); return 0; } printf("Yes! Correct flag is %s\n", input); return 0; }

Compiled Linux binary: mc4
Compiled Windows binary: mc4.exe