#include <bits/stdc++.h>
#pragma comment(linker, "/stack:102400000,102400000")
using namespace std;
const int N = 105;
const int M = 10005;
const int INF = 0x3f3f3f3f;
const int MOD = 1000000007;
const double Pi = acos(-1.0);
int lowbit(int x) { return x & (-x); }
template <class T>
inline T f_min(T a, T b) {
  return a < b ? a : b;
}
template <class T>
inline T f_max(T a, T b) {
  return a > b ? a : b;
}
template <class T>
inline T f_abs(T a) {
  return a > 0 ? a : -a;
}
template <class T>
inline T f_gcd(T a, T b) {
  return b == 0 ? a : f_gcd(b, a % b);
}
template <class T>
inline T f_Lcm(T a, T b) {
  return a / f_gcd(a, b) * b;
}
template <class T>
inline void f_swap(T &a, T &b) {
  T t = a;
  a = b;
  b = t;
}
bool is_digit(char a) {
  if (a >= '0' && a <= '9') return true;
  return false;
}
bool is_lowch(char a) {
  if (a >= 'a' && a <= 'z') return true;
  return false;
}
bool is_upch(char a) {
  if (a >= 'A' && a <= 'Z') return true;
  return false;
}
int main() {
  int n, m;
  string s;
  while (cin >> n >> m) {
    cin >> s;
    int ans = 0;
    for (int i = 0; i < n; ++i)
      if (s[i] == '.') {
        int j;
        for (j = i + 1; j < n; ++j, ans++)
          if (s[j] != '.') break;
        i = j;
      }
    for (int i = 0; i < m; ++i) {
      int x;
      string temp;
      cin >> x >> temp;
      x--;
      if (s[x] != '.') {
        if (temp[0] == '.') {
          if (x == 0) {
            if (x + 1 < n && s[x + 1] == '.') ans++;
          } else if (x == n - 1) {
            if (x - 1 >= 0 && s[x - 1] == '.') ans++;
          } else {
            if (s[x - 1] != '.' && s[x + 1] == '.') ans++;
            if (s[x - 1] == '.' && s[x + 1] != '.') ans++;
            if (s[x - 1] == '.' && s[x + 1] == '.') ans += 2;
          }
        }
        s[x] = temp[0];
        cout << ans << endl;
        continue;
      }
      if (temp[0] != '.') {
        if (x == 0) {
          if (x + 1 < n && s[x + 1] == '.') ans--;
        } else if (x == n - 1) {
          if (x - 1 >= 0 && s[x - 1] == '.') ans--;
        } else {
          if (s[x - 1] != '.' && s[x + 1] == '.') ans--;
          if (s[x - 1] == '.' && s[x + 1] != '.') ans--;
          if (s[x - 1] == '.' && s[x + 1] == '.') ans -= 2;
        }
      }
      cout << ans << endl;
      s[x] = temp[0];
    }
  }
  return 0;
}
