#include <bits/stdc++.h>
using namespace std;
int main() {
    int n;
    int a, b, c, min, max;
    cin>>n;
    cin>>a>>b>>c;
    if(a<b and a<c)min=a;
    if(b<a and b<c)min=b;
    if(c<a and c<b)min=c;
    if(a>b and a>c)max=a;
    if(b>a and b>c)max=b;
    if(c>a and c>b)max=c;
    cout<<0<<endl;
if(a==b and b==c and a==c){cout<<0;}
else {
    if(max==a and min==c)cout<<n-a;
   else if(max==b and min==c)cout<<n-b;
   else if(max==a and min==b)cout<<n-a;
   else if(max==c and min==b)cout<<n-c;
    else if(max==b and min==a)cout<<n-b;
     else if(max==c and min==a)cout<<n-c;
}
 
}