#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,a,b,c;
int main(){
	cin>>n>>a>>b>>c;
	if(c==n){
		cout<<2*n+b-a<<endl;
	}else{
		cout<<2*n-1<<endl;
	}
	return 0;
}

P8220