#include <iostream>
 
using namespace std;
 
class Napis
{
public:
    int l;
};
Napis a1,b1;
 
char *string_merge(char* a,char* b)
{
    char* x;
    x=new char [2*a1.l];
    for(int i=0;i<2*a1.l;i+=2)
    {
        x[i]=*a;
        x[i+1]=*b;
        a++;
        b++;
    }
    return x;
}
 
int main()
{
    string a,b;
    int t;
    cin>>t;
    for(int i=0;i<t;i++)
    {
        cin>>a>>b;
        a1.l=a.length();
        b1.l=b.length();
        if(b1.l<a1.l)
            a1.l=b1.l;
        cout<<string_merge(&a[0],&b[0])<<endl;
    }
    return 0;
}
 

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