include <bits/stdc++.h>

define ll long long

using namespace std; ll a, b, c, d; int main() { cin>>a>>b>>c>>d; if(a > b && a > c && a > d) cout<<a; else if (b > a && b > c && b > d) cout<<b; else if (c > a && c > b && c > d) cout<<c; else cout<<d; return 0; }</p>