1328A - Divisibility Problem.cpp

//                                 ॐ नमः शिवाय
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
 
// Code Written By: Vikash Patel
// Codeforces Profile: https://codeforces.com/profile/vikashpatel
 
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        long long a,b;
        cin>>a>>b;
        long long rem = a%b;
        if(rem==0)
        cout<<"0"<<endl;
        else
        cout<<b-rem<<endl;
    }
    return 0;
}