#include <stdlib.h>

int main(int argc, char* argv[]) {
    if (argc != 3) {
        return 1;
    }
    if (argv[0][0] != 'a') {
        return 2;
    }
    if (argv[1][0] != 'b') {
        return 3;
    }
    if (argv[2][0] != 'c') {
        return 4;
    }
    return 0;
}