#include <iostream>
using namespace std;

int max2(int a, int b) {
    if (a > b) return a;
    else return b;
}
int max4(int a, int b, int c, int d) {
	return max2( max2(a,b), max2(c,d) );
}

int main() {
    int o,p,q,r;
    while (cin >> o >> p >> q >> r ) {
        cout << max4(o, p, q, r) << endl;
    }
}