#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000


int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int T; cin >> T;
    rep(i, T) {
        string S; cin >> S;
        int G = 0, R = 0;
        bool possible = true;
        rep(i, S.length()){
            if (S[i] == 'G') G++;
            else if (S[i] == 'R') R++;
            if ((G - R) < 0) {
                possible = false;
                break;
            }
        }
                    if (G != R) possible = false;
            if (possible) cout << "possible" << endl;
            else cout << "impossible" << endl;
    }

    return 0;
}