#include <bits/stdc++.h>
using namespace std;
int n, m, ar[11][100005];
int rev[11][100005];
long long mx(int start) {
  int val = ar[0][start];
  for (int tmp = 0; tmp < n; ++tmp) {
    for (int row = 1; row < m; ++row) {
      int col = rev[row][val];
      if (col + tmp >= n) {
        return tmp;
      }
      int curVal = ar[row][col + tmp];
      int val2 = ar[0][start + tmp];
      if (curVal != val2) {
        return tmp;
      }
    }
  }
  return n;
}
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 0; i < m; ++i) {
    for (int j = 0; j < n; ++j) {
      scanf("%d", ar[i] + j);
      rev[i][ar[i][j]] = j;
    }
  }
  long long ans = 0;
  for (int i = 0; i < n;) {
    long long mxi = mx(i);
    ans += (mxi * (mxi + 1) / 2ll);
    i += mxi;
  }
  cout << ans;
  return 0;
}
