func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long MOD = 1e9 + 7;   class {    public:     int n, m;     vector<pair<int, int> > V[5555];     bool vis[5555], in[5555];     int ans[5555];     void solve() {       cin >> n >> m;       for (int i = 0; i < m; ++i) {         int u, v;         cin >> u >> v;         V[u].push_back({v, i});       }       for (int i = 1; i <= n; ++i) {         if (!vis[i]) dfs(i);       }       if (two)         cout << 2 <<   n ;       else         cout << 1 <<   n ;       for (int i = 0; i < m; ++i) {         cout << ans[i] + 1 <<    ;       }     }     bool two = 0;     void dfs(int u) {       in[u] = 1;       vis[u] = 1;       for (auto v : V[u]) {         if (!vis[v.first]) {           dfs(v.first);         } else if (in[v.first]) {           ans[v.second] = 1;           two = 1;         }       }       in[u] = 0;     }   } NSPACE;   int main() {     ios_base::sync_with_stdio(false);     cout.tie(0);     cin.tie(0);     NSPACE.solve();   }   