OI-codes/S2OJ/1026/1026.cpp

#include <bits/stdc++.h>

using namespace std;

int t, n, u, v;
vector<int> g[100005];
bool flag, vis[100005];

void dfs(int u, int f) {
    if (flag) return;
    for (int i : g[u]) {
        if (i != f) dfs(i, u);
    }
    if (!vis[u]) {
        if (f == -1 || vis[f]) {
            flag = true;
        } else {
            vis[f] = vis[u] = true;
        }
    }
}

int main() {
    cin >> t;
    while (t--) {
        flag = false;
        for (auto& i : g) i.clear();
        memset(vis, 0x00, sizeof(vis));
        cin >> n;
        for (int i = 1; i < n; i++) {
            cin >> u >> v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
        dfs(1, -1);
        cout << (flag ? "Illyasviel" : "Miyu") << endl;
    }
    return 0;
}