func_code_string: #include <bits/stdc++.h>   using namespace std;   long long powmod(long long a, long long b) {     long long res = 1;     a %= 1000000007;     for (; b; b >>= 1) {       if (b & 1) res = res * a % 1000000007;       a = a * a % 1000000007;     }     return res;   }   struct node {     int x, y;   } f[2203456], ans[2203456];   bool cmp(node x, node y) { return x.x == y.x ? x.y > y.y : x.x < y.x; }   int main() {     int n, k;     cin >> n >> k;     int tot = 0;     for (int i = 0; i < n; i++) {       int a, b;       scanf( %d%d , &a, &b);       f[tot].x = a, f[tot].y = 1;       tot++;       f[tot].x = b, f[tot].y = -1;       tot++;     }     sort(f, f + tot, cmp);     int cnt = 0, ansi = 0, start = 0;     for (int i = 0; i < tot; i++) {       if (cnt == k - 1 && f[i].y == 1) {         start = f[i].x;       }       if (cnt == k && f[i].y == -1) {         ans[ansi].x = start;         ans[ansi].y = f[i].x;         ansi++;       }       cnt += f[i].y;     }     cout << ansi << endl;     for (int i = 0; i < ansi; i++) {       printf( %d %d n , ans[i].x, ans[i].y);     }     return 0;   }   