#include <iostream>
using namespace std;
int main()
{
int a,b,c,d,minim4, maxim4;
cin >>a>>b>>c>>d;
minim4=a;
if (b<minim4) minim4=b;
if (c<minim4) minim4=c;
if (d<minim4) minim4=d;
//alta metoda
maxim4=max(max(a,b),max(c,d));
// si minim4 se poate afla analog
// minim4=min(min(a,b), min(c,d));
int suma=minim4 + maxim4;
cout << suma;
return 0;
}