#include<cstdio> #include<iostream> #include<algorithm> #include<string> #include<queue> #include<vector> #include<functional> #include<cmath> #include<map> #include<stack> #include<set> #include<numeric> #include<limits> #define all(x) (x).begin(),(x).end() #define rall(x) (x).rbegin(),(x).rend() using namespace std; typedef long long ll; typedef pair<int, int> pi; typedef pair<ll, ll> pl; typedef pair<ll, string> pls; int main() { int N; cin >> N; for (int i = 0; i < N; i++) { string s; cin >> s; int red = 0, green = 0, white = 0; bool flag = true; if (s.size() < 3) { cout << "impossible" << endl; continue; } for (int i = 0; i < s.size(); i++) { if (s[i] == 'G') { if (green >= red && white >= 1) { green++; white--; flag = true; } else { cout << "impossible" << endl; break; } } else if (s[i] == 'R') { if (green >= red + 1) { red++; } else { cout << "impossible" << endl; break; } } else { white++; flag = false; } if (i == s.size() - 1) { if (green == red && white >= 0 && flag) { cout << "possible" << endl; } else cout << "impossible" << endl; } } } return 0; }