What is the problem in my code

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
void solve()
{
ll k,a,b;
cin>>k>>a>>b;

ll c=(a+b)%10;

ll sum=0;

sum = sum + a+b+c;

k=k-3;
ll d= (2*(a+b))%10;
ll e= (4*(a+b))%10;
ll f= (8*(a+b))%10;

ll temp=k/4;

ll j=k%4;
if(j==1)
{
sum+=d;
}
else if(j==2)
{
sum+=d+e;
}
else if(j==3)
{
sum+=d+e+f;
}

sum+= (temp*20);

cout<<sum<<endl;

if(sum%3==0)
{

   cout<<"YES"<<"\n";

}
else
{
cout<<“NO”<<"\n";
}
}

int main()
{
ll t;
cin>>t;
while(t–)
{
solve();
}

}

What is the question? And please send the link to your code, don’t paste your code here.

question is “multiple of 3”.
CodeChef: Practical coding for everyone is my solution

problem link is CodeChef: Practical coding for everyone

thanks for the link…haring the link/formatting your code helps in user readability