#include <cstdio>

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;
}