Solution failed on pretest 2

I'm new to Codeforces and have attempted for the first time today.

Following is the solution that I have found while solving the first question.

Here is my solution to the above question:

#include<bits/stdc++.h>
using namespace std;

int main(){
    int no_of_times;
    cin>>no_of_times;   
    for(int l = 0;l < no_of_times;l++){
        int n,k;
        cin>>n>>k;
        if(n == 1 && k == 1){
            cout<<1<<"\n";
        }
        else if(n == 1 && n > k){
            cout<<1<<"\n";
        }
        else if(n > k){
            if(n%2 == 0 && k%2 == 0){
                cout<<0<<"\n";
            }
            else if(n%2 == 0 || k%2 == 0){
                cout<<1<<"\n";
            }
            else{
                cout<<0<<"\n";
            }
        }
        else{
            cout<<(k-n)<<"\n";
        }
    }
}

I've passed pre-test 1, but failed on pretest 2. May I know where was I wrong?