732C - Sanatorium - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
int main(){
    vector<long long> v;
    long long x;
    for(int i =  0; i < 3; i++){
        cin>>x;
        v.push_back(x);
    }
    sort(v.begin(),v.end());
    if(v[1]== v[0] && v[1] == v[2]) cout<<0;
    else if(v[2] - v[1] == 1 && v[2] - v[0] == 1) cout<<0;
    else if(v[0] - v[2] == 1 && v[1] - v[2] == 1) cout<<0;
    else{
        if(v[2] == v[1]) cout<<v[2] -1 - v[0];
        else cout<<(v[2] - 1)*2 - v[1] - v[0];
    }
}