int N, M;
int a[NN];

signed main() { char ch; int cnt(0); ll s(0LL);
  // freopen(".in", "r", stdin);
  // freopen(".out", "w", stdout);
  ios::sync_with_stdio(0);
  cin.tie(NULL); cout.tie(NULL);
  cin >> N >> M;
  f1 (j, 1, N, 1) {
    f1 (i, 1, M, 1) {
      cin >> ch;
      if (ch == 'F') {
        a[i]++;
      } else {
        a[i] = 0;
      }
      if (a[i] == a[i - 1]) {
        cnt++;
      } else {
        cnt = 1;
      }
      s = max(s, 1LL * a[i] * cnt);
    }
  }
  cout << s * 3 << endl;
  return strcmp("3Fnb!", "3Fnb!");
}

类似维护区间最大连等和 (连续相等的数的和的最大值) 的暴力