#include <iostream>
#include <cstdio>
using namespace std;

/*
Add `int max_of_four(int a, int b, int c, int d)` here.
*/

template<typename T>
T my_max(T a, T b)
{
    return (a > b ? a : b);
}

template<typename T, typename ... Types>
T my_max(T a, Types ... types)
{
    return my_max(a, my_max(types...));
}

int max_of_four(int a, int b, int c, int d)
{
    return my_max(a, b, c, d);
}


int main() {
    int a, b, c, d;
    scanf("%d %d %d %d", &a, &b, &c, &d);
    int ans = max_of_four(a, b, c, d);
    printf("%d", ans);

    return 0;
}