func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long MOD = 1e9 + 7;   const long long INF = 2e9;   const long double PI = acos((long double)-1);   const long double EPS = 1e-9;   inline bool isPrime(long long x) {     if (x <= 1) return 0;     if (x <= 3) return 1;     if (!(x % 2) || !(x % 3)) return 0;     long long s = sqrt(1.0 * x) + EPS;     for (long long i = 5; i <= s; i += 6) {       if (!(x % i) || !(x % (i + 2))) return 0;     }     return 1;   }   inline long long fpow(long long n, long long k, long long p = 2e18) {     long long r = 1;     for (; k; k >>= 1) {       if (k & 1) r = r * n % p;       n = n * n % p;     }     return r;   }   inline int inv(int a, long long p = 2e18) { return fpow(a, p - 2, p); }   inline void addmod(int& a, int val, int p = MOD) {     if ((a = (a + val)) >= p) a -= p;   }   inline void submod(int& a, int val, int p = MOD) {     if ((a = (a - val)) < 0) a += p;   }   inline long long gcd(long long a, long long b) {     long long r;     while (b) {       r = a % b;       a = b;       b = r;     }     return a;   }   inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }   const int N = 3e5 + 5;   long long n, m;   long long a[N];   vector<int> adj[N];   void Solve() {     cin >> n;     vector<pair<int, int> > edges;     map<pair<int, int>, int> mp;     for (int i = 1; i < n; i++) {       int u, v;       cin >> u >> v;       adj[u].push_back(v);       adj[v].push_back(u);       edges.push_back({u, v});     }     int cnt = 0;     for (int i = 1; i <= n; i++) {       if (int((adj[i]).size()) == 1 && !mp.count({i, adj[i][0]})) {         mp[{i, adj[i][0]}] = mp[{adj[i][0], i}] = cnt++;       }     }     for (auto p : edges) {       int u = p.first;       int v = p.second;       if (mp.count({u, v})) {         cout << mp[{u, v}] <<   n ;       } else {         cout << cnt++ <<   n ;       }     }   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cout << fixed << setprecision(10);     int query = 1;     int start = 1000 * clock() / CLOCKS_PER_SEC;     while (query--) Solve();     cerr <<   nTime elapsed:   << 1000 * clock() / CLOCKS_PER_SEC - start          <<  ms n ;   }   