#include <bits/stdc++.h>
char s[301488];
bool is_dot[301488];
int answer = 0;
void zahuyach(int whe, char wha) {
  if (wha == '.' && !is_dot[whe]) {
    answer += is_dot[whe - 1];
    answer += is_dot[whe + 1];
  }
  if (wha != '.' && is_dot[whe]) {
    answer -= is_dot[whe - 1];
    answer -= is_dot[whe + 1];
  }
  is_dot[whe] = (wha == '.');
}
int main() {
  int len, q;
  scanf("%d %d", &len, &q);
  scanf("%s", &s[1]);
  for (int i = 1; i <= len; ++i) {
    zahuyach(i, s[i]);
  }
  while (q-- > 0) {
    int whe;
    char wha;
    scanf("%d %c", &whe, &wha);
    zahuyach(whe, wha);
    printf("%d\n", answer);
  }
  return 0;
}
