1238.cpp

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

typedef long long ll;
typedef unsigned int uint;
typedef vector<string> vs;
typedef vector<int> vi;
typedef set<char> sc;
typedef pair<int, int> pii;

#define mp 			make_pair
#define pb 			push_back
#define pi 			3.1415926535897932384626433832795
#define MOD 		1000000007
#define For(n) 	    for(int i=0; i<n; i++)
#define Revl(n) 	for(int i=n; i>=0; i--)
#define FOR(p,k)	for(int i=p; i<k; i++)
#define Sort(x)		sort(x.begin(), x.end())
#define Revs(x)		reverse(s.begin(), x.end())
#define mem(a,b)	memset(a, b, sizeof(a))
#define two(i)		((ll)1<<i)

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        string a, b;
        cin>>a>>b;
        string big;
        int aa = a.size(), bb=b.size();
        (aa>bb) ? big=a : big=b;
        int mi = min(aa, bb);
        For(mi)
        {
            cout<<a[i]<<b[i];
        }
        if(aa!=bb)
            FOR(mi,big.size())
            {
                cout<<big[i];
            }
            cout<<endl;
    }
    return 0;
}