#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
const int N = 3e5 + 100;
const double PI = acos(-1.0);
void fre() {
  freopen("/Users/luras/Desktop/in.txt", "r", stdin);
  freopen("/Users/luras/Desktop/out.txt", "w", stdout);
}
int n, m, i, j, ans, p;
char s[N], ch;
int main() {
  while (~scanf("%d%d", &n, &m)) {
    scanf("%s", s + 1);
    ans = 0;
    for (i = 2; i <= n; i++) {
      if (s[i] == '.' && s[i - 1] == '.') ans++;
    }
    for (i = 1; i <= m; i++) {
      scanf("%d %c", &p, &ch);
      if ((s[p] == '.' && ch == '.') || (s[p] != '.' && ch != '.')) {
        printf("%d\n", ans);
        continue;
      }
      if (s[p] == '.') {
        if (p == 1) {
          if (s[p + 1] == '.') {
            ans--;
          }
        } else {
          if (s[p + 1] == '.') ans--;
          if (s[p - 1] == '.') ans--;
        }
      } else {
        if (p == 1) {
          if (s[p + 1] == '.') ans++;
        } else {
          if (s[p + 1] == '.') ans++;
          if (s[p - 1] == '.') ans++;
        }
      }
      s[p] = ch;
      printf("%d\n", ans);
    }
  }
  return 0;
}
