import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		while (in.hasNext()) {
			int n = in.nextInt();
			int m = in.nextInt();
			StringBuilder sb = new StringBuilder(in.next());
			
			for (int i = 0; i < m; i++) {
				
				int count = 0;
				int x = in.nextInt();
				char c = in.next().charAt(0);
				sb.setCharAt(x-1, c);
				StringBuilder cp = new StringBuilder(sb.toString());
				
				int length = cp.length();
				int j = 0;
				while (j < length - 1) {
					if (cp.charAt(j) == '.' && cp.charAt(j+1) == '.') {
						cp.replace(j, j+2, ".");
						count++;
						length = cp.length();
					} else {
						j++;
					}
				}
				System.out.println(count);
			}	
                }
	}
}