#include <cstdint>
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <algorithm>

using namespace std;

void possible()
{
	cout << "possible" << endl;
}

void impossible()
{
	cout << "impossible" << endl;
}

void resolve(const string& s)
{
	vector<string::size_type> index_list(s.length());
	string::size_type indexW = string::npos;
	string::size_type indexG = string::npos;
	string::size_type indexR = string::npos;
	int countW = 0;
	int countG = 0;
	int countR = 0;
	for (string::size_type i = 0; i < s.length(); i++) {
		char ch = s[i];
		switch (ch) {
		case 'W':
			countW++;
			index_list[i] = indexW;
			indexW = i;
			break;
		case 'G':
			countG++;
			index_list[i] = indexG;
			indexG = i;
			break;
		case 'R':
			countR++;
			index_list[i] = indexR;
			indexR = i;
			break;
		}
	}
	if (countW < countG || countG != countR) {
		impossible();
		return;
	}
	for (int i = 0; i < countR; i++) {
		if (indexW > indexG || indexG > indexR) {
			impossible();
			return;
		}
		indexW = index_list[indexW];
		indexG = index_list[indexG];
		indexR = index_list[indexR];
	}
	possible();
}

int main()
{
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		string s;
		cin >> s;
		resolve(s);
	}
	return 0;
}