#include <iostream>
#include <string>
using namespace std;
int main()
{
    int T; cin>>T;
    while (T--) {
        string s; cin>>s;
        int n=s.size();
        int c[128]={};
        int& r=c['R'], &g=c['G'], &w=c['W'];
        bool possible=true;
        for(int i=0;i<n;++i) {
            if (g<r or w<r) { possible=false; break; }
            c[s[i]]++;
        }
        for(int i=n-1;i>=0&&s[i]!='R'&&possible;--i)
            if (s[i]=='W' or s[i]=='G') possible=false;
        if (r!=g or r>w) possible=false;
        cout<<(possible?"possible":"impossible")<<endl;
    }
}