#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int v, w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;
int INF = INT_MAX / 4;

int main() {
	int T; cin >> T;
	while (T--) {
		string S; cin >> S;
		int w = 0, g = 0, r = 0;
		bool ok = true;
		for (int i = 0; i < S.length(); i++) {
			if (S[i] == 'W') w++;
			if (S[i] == 'G') g++;
			if (S[i] == 'R') r++;
			if (w < g) ok = false;
			if (g < r) ok = false;
		}
		if (g != r) ok = false;
		cout << (ok ? "possible" : "impossible") << endl;
	}
}