func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1e9 + 7;   const int C = 26;   void add(int &x, int y) {     x += y;     while (x >= MOD) x -= MOD;     while (x < 0) x += MOD;   }   int fix(int x) {     while (x >= MOD) x -= MOD;     while (x < 0) x += MOD;     return x;   }   int pw(int a, int b) {     int ret = 1;     while (b) {       if (b & 1) ret = 1ll * ret * a % MOD;       b >>= 1;       a = 1ll * a * a % MOD;     }     return ret;   }   const int MAXN = 105;   int n, m, dp[MAXN][MAXN], l[MAXN][MAXN], r[MAXN][MAXN];   void solve() {     cin >> n >> m;     for (int i = 0; i < n; i++) {       int k;       cin >> k;       for (int rep = 0; rep < k; rep++) {         int a, b;         cin >> a >> b;         --a;         for (int j = a; j < b; j++) {           r[i][j] = b;           l[i][j] = a;         }       }     }     for (int b = m - 1; ~b; --b) {       for (int e = b + 1; e <= m; e++) {         for (int k = b; k < e; k++) {           int val = 0;           for (int i = 0; i < n; i++)             if (b <= l[i][k] && r[i][k] <= e) ++val;           dp[b][e] = max(dp[b][e], val * val + dp[b][k] + dp[k + 1][e]);         }       }     }     cout << dp[0][m] <<   n ;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int te = 1;     for (int w = 1; w <= te; w++) {       solve();     }     return 0;   }   