Wrong answer in one test case

#1

i am getting wrong answer in one test case what is the problem with my code
my code:
#include
#include
using namespace std;
int main() {
int t;
cin>>t;
while(t–)
{
string a,b;
cin>>a>>b;
for(int i=0;i<a.length();i++)
{
if(a[i]!=b[i])
cout<<“1”;
else
cout<<“0”;
}
}
}

#2

@sawan_verma you are forgetting to put the end line as this program is running for t no of test case