#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for (ll i = (s); i < (ll)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for (ll i = (ll)(s - 1); i >= (ll)(e); i--)
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;

template <typename T, typename U>
bool chmax(T& a, const U& b) {
    if (a >= b) return false;
    a = b;
    return true;
}
template <typename T, typename U>
bool chmin(T& a, const U& b) {
    if (a <= b) return false;
    a = b;
    return true;
}

void yes_no(bool f, string yes = "Yes", string no = "No") {
    cout << (f ? yes : no) << "\n";
}

void solve() {
    string s;
    cin >> s;
    int r = 0, g = 0, w = 0;
    int ok = true;
    repr(i, s.size()) {
        if (s[i] == 'R') {
            ++r;
        } else if (s[i] == 'G') {
            ++g;
            ok &= r >= g;
        } else {
            ++w;
            ok &= r > 0 && g > 0;
        }
    }
    ok &= r == g;
    ok &= w > r;
    yes_no(ok, "possible", "impossible");
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int t = 1;
    // multi-testcase
    cin >> t;
    rep(ti, t) solve();
    return 0;
}