import sys
readline = sys.stdin.readline

N, M = map(int, readline().split())
S = list(input())
mod = 10 ** 9 + 7
G = [[] for i in range(N)]
for i in range(M):
    u, v = map(int, readline().split())
    u, v = u - 1, v - 1
    G[u].append(v)
    G[v].append(u)
    
dp = [0] * N
for i in range(N):
    if S[i] == "P":
        dp[i] = 1

for i in range(N):
    if S[i] == "D":
        for u in G[i]:
            if S[u] == "P":
                dp[i] += dp[u]
                dp[i] %= mod
                
for i in range(N):
    if S[i] == "C":
        for u in G[i]:
            if S[u] == "D":
                dp[i] += dp[u]
                dp[i] %= mod
                
ans = 0
for i in range(N):
    if S[i] == "A":
        for u in G[i]:
            if S[u] == "C":
                dp[i] += dp[u]
                dp[i] %= mod
        ans += dp[i]
        ans %= mod
                
print(ans)