#include <stdio.h>
#include <stdlib.h>

int gcd(int a, int b) {
    printf("gcd(%d, %d)\n", a, b);
    if (b == 0) {
	return a;
    } else {
	return gcd(b, a % b);
    }
}

int main(int argc, char *argv[]) {
    int a, b;

    if (argc <= 2) {
	printf("引数が足りません\n");
	return 1;
    };
    a = strtol(argv[1], NULL, 10);
    b = strtol(argv[2], NULL, 10);
    printf("gcd(%d, %d) = %d\n", a, b, gcd(a, b));
    return 0;
}