#include <iostream>
#include <queue>
#include <string>
#include <algorithm>

using namespace std;

auto T=0;
queue<int> que;
queue<int> g_que;

void input(){
    cin >> T;
}

void solve(){
    for(int i=0; i<T; i++){
        string s;
        cin >> s;
        while(!que.empty())que.pop();
        while(!g_que.empty())g_que.pop();

        reverse(s.begin(), s.end());
        
        if(s[0]!='R' )printf("Impossible\n");
        else printf("possible\n");
        continue;

        for(int j=0;j< s.length();j++){
            cout << s[j]<<endl;
            switch(s[j]){
                case 'R':
                    que.push(1);
                case 'G':
                    if(que.empty()) break;
                    que.pop();
                    g_que.push(1);
                    break;
                case 'W':
                    if(g_que.empty()) break;
                    g_que.pop();
                    break;            
            }
        }
        if(!que.empty()||!g_que.empty()) printf("Impossible\n");
        else printf("possible\n");
    }
}

int main(){
    input();
    solve();
}