def f(v):
    if S[v] == 'A': return 1
    n = 0

    for u in g[v]:
        if (S[v] == 'P' and S[u] == 'D') or (S[v] == 'D' and S[u] == 'C') or (S[v] == 'C' and S[u] == 'A'):
            if dp[u] > -1: n += dp[u]
            else: n += f(u)
    dp[v] = n % MOD

    return n

MOD = 10**9+7
N, M = list(map(int, input().split()))
S = input()
g = [[] for i in range(N)]
for i in range(M):
    u, v = list(map(int, input().split()))
    u -= 1; v -= 1
    g[u].append(v)
    g[v].append(u)

dp = [-1] * N
ans = 0
for i in range(N):
    if dp[i] > -1: continue
    f(i)

    if S[i] == 'P': ans += dp[i]; ans %= MOD

print(ans%MOD)