MOD = 10 ** 9 + 7

n, m = map(int, input().split())
S = input()
edges = [[] for _ in range(n)]
for _ in range(m):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    edges[u].append(v)
    edges[v].append(u)
    
cnt = [0] * n
for f, t in zip("PDC", "DCA"):
    for i, s in enumerate(S):
        if s == f:
            if f == "P":
                cnt[i] = 1
            for j in edges[i]:
                if S[j] == t:
                    cnt[j] += cnt[i]
                    
ans = 0
for i, s in enumerate(S):
    if s == "A":
        ans += cnt[i]

print(ans % MOD)