#include<bits/stdc++.h>
using namespace std;

int main()
{
	int n,m,p,q;
	cin>>n>>m>>p>>q;
	if(p<n&&q<(long long)n*m)cout<<"Program ends with return value 0.";
	else cout<<"Segmentation fault.";
	return 0;
}

#1#2测试点错误