
#include<iostream>
using namespace std;
int main()
{
    int a,b;
    cin >> a >> b;
    int t = (2 * a)  + 100 ;
    if(t-b < 0){
        cout << 0 << endl;
    }
    else{
        cout << t-b << endl;
    }
}

#include <iostream>
using namespace std;
int main(void) 
{
	int x, y;
	cin >> x >> y;
	if (x > y) {
		if ((y + 3) > x) {
			cout << "Yes" << endl;
		}
		else {
			cout << "No" << endl;
		}
	}
	if (y > x) {
		if ((x + 3) > y) {
			cout << "Yes" << endl;
		}
		else {
			cout << "No" << endl;
		}
	}
}