from functools import lru_cache
MOD = 10 ** 9 + 7
N, M = map(int, input().split())
S = input()
UV = [list(map(int, input().split())) for _ in range(M)]
E = [[] for _ in range(N)]
A = ["P", "D", "C", "A"]

for u, v in UV:
    u -= 1
    v -= 1
    a = A.index(S[u])
    if a < 3 and S[v] == A[a + 1]:
        E[u].append(v)
    if 0 < a and S[v] == A[a - 1]:
        E[v].append(u)

#@lru_cache()
def dfs(x):
    if S[x] == "A":
        return 1
    ret = 0
    for v in E[x]:
        ret += dfs(v)
    return ret

ans = 0
for i in range(N):
    if S[i] == "P":
        ans += dfs(i)
        ans %= MOD
print(ans)