#include <stdio.h>
int max(int x, int y);
int main(void) {
    int a,b,c,d;
a = 1;
    b = 5;
    c = 3;
    d = 4;
    printf("%d\n", max(max(a, b), max(c, d)));

	return 0;
}
int max(int x, int y){
if (x > y) {
        return x;
    } else {
        return y;
    }

}