I Had A Problem solving the "lucky?" problem. And I Need just a little bit of help to solve it.

--> this is the link to the problem : https://mirror.codeforces.com/contest/1676/problem/A

--> and this is my source code :

include

include

using namespace std;

int main(){ string num; int testCases,sum1,sum2;

cin>>testCases;

for(int k=0;k<=testCases-1;k++){

    cin>>num;

    for(int i=0;i<=2;i++){
        sum1=sum1+num[i];
    }//end for i - first 3-digits -

    for(int j=3;j<=5;j++){
        sum2=sum2+num[j];
    }//end for j - Second 3-digits -

if(sum1==sum2){
    cout<<"YES\n";
}//end if - sum1==sum2 -
else {
    cout<<"NO\n";
}//end else

}//end for k-test cases-

return 0;

}//end main

So If Anybody can help I Would be super appreciative.