#include <bits/stdc++.h>
#define LL long long
#define ULL unsigned long long
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++)
using namespace std;
int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int N;
	cin >> N;
	string S;
	REP( i, N )
	{
		cin >> S;
		auto pos = S.find_last_of( 'R' );
		if( S.find( 'G', pos + 1 ) != string::npos ||
		    S.find( 'W', pos + 1 ) != string::npos  )
		{
			cout << "impossible" << endl;
			continue;
		}
		int countG{},countR{};
		REP( i, (int)S.size() )
		{
			if( S[i] == 'G' )
			{
				countG++;
			}
			if( S[i] == 'R')
			{
				countR++;
			}
		}
		cout << ( (countG > 0 && countR > 0 ) ? "possible" : "impossible" ) << endl;
	}
	return 0;
}