#include <iostream> #include <algorithm> #include <vector> #include <cstdio> #include <cstdlib> using namespace std; typedef __int64 LL; LL gcd(LL a, LL b) { if(b==0) return a; return gcd(b, a%b); } int main() { LL a, b, c; int T; vector<LL> v; scanf("%d", &T); while(T--) { scanf("%I64d%I64d%I64d", &a, &b, &c); LL temp = gcd(a, b); v.clear(); int cnt = 0; for(LL i=1; i*i<=temp; ++i) { if(temp%i==0) { v.push_back(i); if(i*i!=temp) v.push_back(temp/i); } } sort(v.begin(), v.end()); if(v.size() >= c) printf("%I64d ", v[v.size()-c]); else printf("-1 "); } return 0; }