#include<iostream>
#include<string>
using namespace std;
int main(){
    int N;
    int Gcheck,Rcheck;
    string input;
    bool flag;
    cin >> N;
    for(int i=0;i<N;i++){
        flag = true;
        Gcheck = 0;
        Rcheck = 0;
        cin >> input;
        for(int j=0;j<input.length();j++){
            if(input[j] == 'W') Gcheck++;
            else if(input[j] == 'R') Rcheck--;
            else{
                Gcheck--;
                Rcheck++;
            }
            if(Gcheck<0 || Rcheck < 0){
                flag = false;
                break;
            }
        }
        if(flag && Rcheck == 0) cout << "possible" << endl;
        else cout << "impossible" << endl;
    }
    return 0;
}