// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>
#define ll long long
#define REP(i, n) for(auto i=0;i<n;i++)
#define pb push_back
using namespace std;

void solve()
{
  int a, b, c, n;
  cin>>a>>b>>c>>n;
  cout<<a+b+c+n<<"\n";
    
}
int main() {
    // Write C++ code here
    // std::cout << "Hello world!";

    // int T;
    // cin>>T;
    // while(T-->0)
    solve();
    return 0;
}