#include <bits/stdc++.h>
using namespace std;
const int MAXN = 300002;
int n, m, l[MAXN * 4], r[MAXN * 4], d[MAXN * 4], id[MAXN];
string s;
void input() {
  scanf("%d%d", &n, &m);
  cin.ignore(1);
  getline(cin, s);
  s = '0' + s;
}
void init(int x, int left, int right) {
  l[x] = left;
  r[x] = right;
  if (left == right) {
    d[x] = 0;
    id[left] = x;
    return;
  }
  int mid = (left + right) / 2;
  init(x * 2, left, mid);
  init(x * 2 + 1, mid + 1, right);
  d[x] = d[x * 2] + d[x * 2 + 1];
  if (s[mid] == '.' && s[mid + 1] == '.') d[x]++;
}
void update(int a) {
  int x = id[a];
  x /= 2;
  while (x > 0) {
    d[x] = d[x * 2] + d[x * 2 + 1];
    if (s[r[x * 2]] == '.' && s[l[x * 2 + 1]] == '.') d[x]++;
    x /= 2;
  }
}
int main() {
  input();
  init(1, 1, n);
  int a;
  char b;
  for (int q = 1; q <= m; q++) {
    scanf("%d %c", &a, &b);
    if ((s[a] == '.' && b == '.') || (s[a] != '.' && b != '.')) {
      printf("%d\n", d[1]);
      continue;
    }
    s[a] = b;
    update(a);
    printf("%d\n", d[1]);
  }
}
