#include <bits/stdc++.h>

    using namespace std;

    typedef long long ll;
    #define fast_cin()                    \
        ios_base::sync_with_stdio(false); \
        cin.tie(NULL);                    \
        cout.tie(NULL)

    void solve()
    {
        string a,b,res;
        ll n = 0;
        cin >> a >> b >> n;
        while (res.length()<n){
            res= a+b;
            a=b;
            b=res;
        }
        cout<<res[n+1]<<endl;

    }
    int main()
    {
        fast_cin();
        ll t;
        cin >> t;
        for (int it = 1; it <= t; it++)
        {
            solve();
        }
        return 0;
    }