int max_of_four(int a, int b, int c, int d) {
    int largest = std::max({a, b, c, d});
    return largest;
}

int max_of_four(int a, int b, int c, int d){
    if(a>b && a>c && a>d){
        return a;
    }
    else if(b>c && b>d){
        return b;
    }
    else if(c>d){
        return c;
    }
    return d;
}

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

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

int max_of_four(int a, int b, int c, int d) {
    int nums[] = {a, b, c, d};
    int mx = nums[0]; 
    
    for (int i = 1; i < 4; i++) {
        if(nums[i] > mx) {
            mx = nums[i]; 
        }        
    }   
    return mx; 
}
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;
}