include <bits/stdc++.h>

include <cmath>

using namespace std; /* run this program using the console pauser or add your own getch, system("pause") or input loop / int main(int argc, char* argv) { long long a,b,c,d; cin>>a>>b>>c>>d; if(((a==b&&c==b)||(a==c&&c==d)||(b==c&&c==d)||a==0||b==0||d==0||c==0)||a>=b+c+d||b>=a+c+d||c>=a+b+d||d>=a+b+c){ cout<<"No"; } else{ cout<<a+b+c+d; } }