#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

int main(void) {
	int n;
	cin >> n;
	for(int i=0;i<n;i++){
		string s;
		cin >> s;
		int cnt = 0;
		bool f = true;
		for(int i=0;i<s.size();i++){
			if(s[i] == 'G')cnt++;
			else if(s[i] == 'R'){
				cnt--;
			}
			if(cnt < 0)f = false;
		}

		if(f && cnt == 0)cout << "possible" << endl;
		else cout << "impossible" << endl;
	}
	return 0;
}