func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1E5 + 10;   const int inf = 1 << 30;   long long read() {     long long a = 0;     char b = 1, c;     do       if ((c = getchar()) == 45) b = -1;     while (c < 48 || c > 57);     do a = (a << 3) + (a << 1) + (c & 15);     while ((c = getchar()) > 47 && c < 58);     return a * b;   }   void write(long long x, char c) {     if (x < 0) putchar(45), x = -x;     char a[20], s = 0;     do a[++s] = x % 10 | 48;     while (x /= 10);     do putchar(a[s]);     while (--s);     putchar(c);   }   int fa[N], _fa[N];   int find(int x) { return fa[x] ^ x ? fa[x] = find(fa[x]) : x; }   int _find(int x) { return _fa[x] ^ x ? _fa[x] = _find(_fa[x]) : x; }   vector<int> q, _q;   int main() {     int n = read(), y = read(), z = read();     write(n - 1 - max(y, z),   n );     for (int i = 1; i <= n; ++i) fa[i] = _fa[i] = i;     while (y--) {       int u = find(read()), v = find(read());       if (u > v) swap(u, v);       fa[v] = u;     }     while (z--) {       int u = _find(read()), v = _find(read());       if (u > v) swap(u, v);       _fa[v] = u;     }     for (int i = 2; i <= n; ++i) {       int u = find(i), v = _find(i);       if (u ^ 1 && v ^ 1) {         fa[u] = _fa[v] = 1;         printf( %d 1 n , i);       }     }     for (int i = 2; i <= n; ++i) {       if (find(i) == i) q.push_back(i);       if (_find(i) == i) _q.push_back(i);     }     for (int i = min(q.size(), _q.size()); i--;) printf( %d %d n , q[i], _q[i]);   }   