#include <bits/stdc++.h>
using namespace std;
int tc = 1;
const int M = 1e9 + 7;
const long long Inf = (long long)2e18 + 5;
const int N = 2e5 + 5;
std::vector<long long> a[N];
int solve() {
  int a;
  cin >> a;
  int z = 0;
  int bg = 0;
  int xx = 0;
  int mx = 0;
  long long ans = 0LL;
  for (z = 0; z < a; z++) {
    int n;
    cin >> n;
    mx = 0;
    for (int i = 0; i < n; i++) {
      int x;
      cin >> x;
      mx = max(mx, x);
    }
    if (z > 0) {
      if (xx > mx) {
        ans += (long long)(xx - mx) * n;
        bg += n;
      } else {
        ans += (long long)(mx - xx) * bg;
        xx = mx;
        bg += n;
      }
    } else {
      xx = mx;
      bg += n;
    }
  }
  cout << ans << endl;
  return 0;
}
int main() {
  int test = 1;
  while (test--) solve();
  return 0;
}
