#include<bits/stdc++.h>
using namespace std;
#define T int t; cin>>t; while(t--)
int main()
{
int x, y;
cin>>x>>y;
int rp = y;
while(y%3!=0) y++;
cout<<y-rp<<endl;
return 0;
}
I2luY2x1ZGU8Yml0cy9zdGRjKysuaD4KdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCiNkZWZpbmUgVCBpbnQgdDsgY2luPj50OyB3aGlsZSh0LS0pCgppbnQgbWFpbigpCnsKCiAgICBpbnQgeCwgeTsKICAgIGNpbj4+eD4+eTsKCiAgICBpbnQgcnAgPSB5OwoKICAgIAogICAgd2hpbGUoeSUzIT0wKSB5Kys7CgogICAgY291dDw8eS1ycDw8ZW5kbDsKICAgIHJldHVybiAwOwp9