#include<bits/stdc++.h>
using namespace std;


int main(){
    int x,y,a,b;
    cin>>x>>y>>a>>b;
    int v=min(x,y)+abs(x-y);
    if(x!=y)cout<<v<<endl;
    else{
        if(a==b&&x>a)cout<<v+1<<endl;
        else cout<<v<<endl;
    }

    return 0;
}