func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e5 + 7;   const int inf = INT_MAX;   const long long inff = 1e18;   const long long mod = 1e9 + 7;   int n, m, x, y;   int a[maxn], p[maxn];   int b[maxn];   int dp1[maxn], dp2[maxn];   vector<int> v;   int32_t main() {     ios::sync_with_stdio(0);     cin.tie(0);     cin >> n >> m;     for (int i = 1; i <= n; i++) {       cin >> x >> y;       p[x]++;       p[y + 1]--;     }     for (int i = 1; i <= m; i++) a[i] = a[i - 1] + p[i], b[m - i + 1] = a[i];     for (int i = 1; i <= m; i++) {       auto now = upper_bound((v).begin(), (v).end(), a[i]);       if (now == v.end())         v.push_back(a[i]);       else         v[now - v.begin()] = a[i];       dp1[i] = ((int)(v).size());     }     v.clear();     for (int i = 1; i <= m; i++) {       auto now = upper_bound((v).begin(), (v).end(), b[i]);       if (now == v.end())         v.push_back(b[i]);       else         v[now - v.begin()] = b[i];       dp2[i] = ((int)(v).size());     }     int ans = 0;     for (int i = 0; i <= m; i++) ans = max(ans, dp1[i] + dp2[m - i]);     cout << ans <<   n ;   }   