#include<bits/stdc++.h>
using namespace std;
#define int long long
const int mod=1e9;

signed main()
{
    int a,b;
    cin>>a>>b;
    a=a*2+100;
    cout<<max(0ll,a-b)<<endl;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main(){
    int a,b;
    cin>>a>>b;
    if (15<=a+b&&8<=b){
        cout<<1;
    }
    else if (10<=a+b&&3<=b){
        cout<<2;
    }
    else if (3<=a+b){
        cout<<3;
    }
    else{
        cout<<4;
    }
}
