#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  string s;
  cin >> s;
  int now = 0;
  for (int i = 0; i < n - 1; ++i)
    if (s[i] == '.' && s[i + 1] == '.') ++now;
  while (m--) {
    int pos;
    char ch;
    cin >> pos >> ch;
    --pos;
    if (ch == '.') {
      if (s[pos] == '.') {
        cout << now << endl;
        continue;
      }
      if (pos < n - 1 && s[pos + 1] == '.') ++now;
      if (pos && s[pos - 1] == '.') ++now;
      s[pos] = ch;
    } else {
      if (s[pos] != '.') {
        cout << now << endl;
        continue;
      }
      if (pos < n - 1 && s[pos + 1] == '.') --now;
      if (pos && s[pos - 1] == '.') --now;
      s[pos] = ch;
    }
    cout << now << endl;
  }
}
