#include <bits/stdc++.h>
using namespace std;
template <typename A, typename B>
string to_string(pair<A, B> p);
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
const int mod = 1e9 + 7;
int sum(int a, int b) { return (a + b) % mod; }
int sub(int a, int b) { return (a + mod - b) % mod; }
int mul(int a, int b) { return (1ll * a * b) % mod; }
int power(int a, int b) {
  int res = 1;
  while (b) {
    if (b & 1) res = mul(res, a);
    b >>= 1;
    a = mul(a, a);
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int N, M;
  cin >> N >> M;
  string str;
  cin >> str;
  set<pair<int, int> > S;
  int l = -1, r = -1;
  for (int i = 0; i < N; i++) {
    if (str[i] == '.') {
      if (l == -1) {
        l = r = i;
      } else {
        r++;
      }
    } else {
      if (l != -1 && r != -1) S.insert(pair<int, int>(l, r));
      l = r = -1;
    }
  }
  if (l != -1 && r != -1) S.insert(pair<int, int>(l, r));
  42;
  int res = 0;
  for (auto& x : S) res += x.second - x.first;
  while (M--) {
    int pos;
    char c;
    cin >> pos >> c;
    pos--;
    if (str[pos] == '.') {
      if (c != '.') {
        auto it = S.lower_bound(pair<int, int>(pos, -1));
        if (it == S.end() || it->first > pos) it--;
        l = it->first;
        r = it->second;
        S.erase(pair<int, int>(l, r));
        res -= (r - l);
        int m = pos - 1;
        if (l <= m) {
          S.insert(pair<int, int>(l, m));
          res += (m - l);
        }
        m = pos + 1;
        if (m <= r) {
          S.insert(pair<int, int>(m, r));
          res += (r - m);
        }
        str[pos] = c;
      }
    } else {
      if (c == '.') {
        if (pos - 1 >= 0 && pos + 1 <= N - 1 && str[pos - 1] == '.' &&
            str[pos + 1] == '.') {
          auto it1 = S.lower_bound(pair<int, int>(pos, -1));
          it1--;
          auto it2 = S.lower_bound(pair<int, int>(pos, -1));
          int l1 = it1->first;
          int r1 = it1->second;
          int l2 = it2->first;
          int r2 = it2->second;
          res -= (r1 - l1);
          res -= (r2 - l2);
          res += (r2 - l1);
          S.erase(pair<int, int>(l1, r1));
          S.erase(pair<int, int>(l2, r2));
          S.insert(pair<int, int>(l1, r2));
        } else if (pos - 1 >= 0 && str[pos - 1] == '.') {
          auto it1 = S.lower_bound(pair<int, int>(pos, -1));
          it1--;
          int l1 = it1->first;
          int r1 = it1->second;
          res -= (r1 - l1);
          res += (pos - l1);
          S.erase(pair<int, int>(l1, r1));
          S.insert(pair<int, int>(l1, pos));
        } else if (pos + 1 <= N - 1 && str[pos + 1] == '.') {
          auto it1 = S.lower_bound(pair<int, int>(pos, -1));
          int l1 = it1->first;
          int r1 = it1->second;
          res -= (r1 - l1);
          res += (r1 - pos);
          S.erase(pair<int, int>(l1, r1));
          S.insert(pair<int, int>(pos, r1));
        } else {
          S.insert(pair<int, int>(pos, pos));
        }
        str[pos] = c;
      }
    }
    cout << res << '\n';
  }
  return 0;
}
