#include <bits/stdc++.h>
#if __has_include(<cpp-dump/cpp-dump.hpp>)
#include <cpp-dump/cpp-dump.hpp>
#endif
using namespace std;
using ll = int64_t;
#define all(a) a.begin(), a.end()
#define rep(i, s, e) for (ll i = s; i < e; ++i)
#define asort(a) stable_sort(all(a))
#define rsort(a) stable_sort(a.rbegin(), a.rend())
#define sum(a) reduce(all(a))
constexpr double degrees(double a) { return (a * 180.0) / numbers::pi; }
constexpr double radians(double a) { return (a * numbers::pi) / 180.0; }

int main(int, [[maybe_unused]] char* argv[]) {
#ifdef DEBUG
  freopen(argv[1], "r", stdin);
#endif

  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(15);

  int N, M;
  cin >> N >> M;
  vector<string> S(N);
  rep(i, 0, N) cin >> S[i];

  map<int, int> event;
  for (auto si : S) {
    rep(j, 0, M) {
      if (si[j] == 'o') event[j]++;
    }
  }

  int ans = 0;
  for (auto si : S) {
    bool uniq = false;
    rep(j, 0, M) {
      if (si[j] == 'o') {
        if (event[j] == 1) {
          uniq = true;
        } else {
          uniq = false;
          break;
        }
      }
    }
    if (uniq) ans++;
  }
  println("{}", ans);

  return 0;
}