# -*- coding: utf-8 -*-
N, Q = map(int, input().split())
s = input()
t = [''] * Q
d = [''] * Q
for i in range(Q):
    t[i], d[i] = input().split()
G = [1] * N
S = list(s)

for i in range(Q):
    if t[i] == s[0]:
        if d[i] == 'R':
            G[1] += G[0]
            G[0] = 0
        elif d[i] == 'L':
            G[0] = 0
            
    for j in [k for k, x in enumerate(S[1:N-1], 1) if x == t[i]]:
        if d[i] == 'R':
            G[j + 1] += G[j]
            G[j] = 0
        elif d[i] == 'L':
            G[j - 1] += G[j]
            G[j] = 0
    
    if t[i] == s[N - 1]:
        if d[i] == 'R':
            G[N - 1] = 0
        elif d[i] == 'L':
            G[N - 2] += G[N - 1]
            G[N - 1] = 0
 
print(sum(G))