#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

bool solve(const string& s)
{
    int n = s.size();
    if(s == string(n, 'W'))
        return false;

    int cnt = 0;
    for(int i=0; i<n; ++i){
        if(s[i] == 'G'){
            ++ cnt;
        }
        else if(s[i] == 'R'){
            -- cnt;
            if(cnt < 0)
                return false;
        }
    }

    if(cnt == 0)
        return true;
    else
        return false;
}

int main()
{
    int t;
    cin >> t;

    while(--t >= 0){
        string s;
        cin >> s;
        if(solve(s))
            cout << "possible" << endl;
        else
            cout << "impossible" << endl;
    }

    return 0;
}