n,m = map(int,input().split())
s = input()
g = [[] for _ in range(n)]
for _ in range(m):
    a,b = map(int,input().split())
    g[a-1].append(b-1)
    g[b-1].append(a-1)

MOD = 10**9+7
r = [int(si=="P") for si in s]
for A,B in ["PD","DC","CA"]:
    nr = [0]*n
    for i in range(n):
        if r[i] and s[i] == A:
            for c in g[i]:
                if s[c] == B:
                    nr[c] += r[i]
                    nr[c] %= MOD
    r = nr
print(sum(r)%MOD)