#include <iostream>
#include <unordered_map>
#include <string>
#include <algorithm>

int main() {
    std::unordered_map<std::string, int> roots;
    for (int i = 1; i * i <= 1000000000; i++) {
        if (i % 10 == 0) continue;
        int sq = i * i;
        std::string s = std::to_string(sq);
        auto t = s;
        std::sort(t.rbegin(), t.rend());
        if (!roots[t]) roots[t] = sq;
    }
    int T;
    std::cin >> T;
    while (T--) {
        std::string N;
        std::cin >> N;
        if (N.size() == 10) {
            std::cout << 1 << std::endl;
            continue;
        }
        std::sort(N.rbegin(), N.rend());
        int result = -1;
        if (roots[N]) result = roots[N];
        while (N.back() == '0') {
            N.pop_back();
        if (roots[N]) result = roots[N];
        }
        std::cout << result << std::endl;
    }
}