package main

import . "fmt"

func main() {
	var n, m int
	var s string
	Scan(&n,&m,&s)
	a := make([]int, 0, n+m)
	w := make([]int, 0, n)
	c := make([]int, 0, m)
	for i, ch := range s {
		switch ch {
			case 'A':
				a = append(a, i)
			case 'W':
				w = append(w, i)
			case 'C':
				c = append(c, i)
		}
	}
	for len(c) > 0 {
		if c[0] < a[0] {
			Println("No")
			return
		}
		c = c[1:]
		a = a[1:]
	}
	for len(w) > 0 {
		if a[len(a)-1] < w[len(w)-1] {
			Println("No")
			return
		}
		a = a[:len(a)-1]
		w = w[:len(w)-1]
	}
	Println("Yes")
}