There are N squares numbered 1 to N from left to right. Each square has a character written on it, and Square i has a letter s_i. Besides, there is initially one golem on each square.

Snuke cast Q spells to move the golems.

The i-th spell consisted of two characters t_i and d_i, where d_i is `L` or `R`. When Snuke cast this spell, for each square with the character t_i, all golems on that square moved to the square adjacent to the left if d_i is `L`, and moved to the square adjacent to the right if d_i is `R`.

However, when a golem tried to move left from Square 1 or move right from Square N, it disappeared.

Find the number of golems remaining after Snuke cast the Q spells.

Constraints

* 1 \leq N,Q \leq 2 \times 10^{5}
* |s| = N
* s_i and t_i are uppercase English letters.
* d_i is `L` or `R`.

Input

Input is given from Standard Input in the following format:


N Q
s
t_1 d_1
\vdots
t_{Q} d_Q


Output

Print the answer.

Examples

Input

3 4
ABC
A L
B L
B R
A R


Output

2


Input

8 3
AABCBDBA
A L
B R
A R


Output

5


Input

10 15
SNCZWRCEWB
B R
R R
E R
W R
Z L
S R
Q L
W L
B R
C L
A L
N L
E R
Z L
S L


Output

3
import sys 
input=sys.stdin.readline
N,Q=map(int,input().split())
S=input()
move=[input().split() for i in range(Q)]
def check(i):
    now=i
    for m in move:
        if S[now]==m[0]:
            if m[1]=="L":
                now-=1
            else:
                now+=1
        if now<0:
            return -1
        if now>=N:
            return 1
    return 0
Lmin=-1
Lmax=N
Rmin=-1
Rmax=N
C={(1,2)}
while True:
    if len(C)==0:
        break
    c=C.pop()
    now=N*c[0]//c[1]
    x=check(now)
    if x==0:
        if Lmax>now:
            Lmax=now
            C|={(c[0]*2-1,c[1]*2)}
        if Rmin<now:
            Rmin=now
            C|={(c[0]*2+1,c[1]*2)}
    elif x==1:
        if now<Rmax:
            Rmax=now
            C|={(c[0]*2-1,c[1]*2)}
    elif x==-1:
        if Lmin<now:
            Lmin=now
            C|={(c[0]*2+1,c[1]*2)}
print(Rmax-Lmin-1)