p = 10**9+7
N,M = map(int,input().split())
S = input().strip()
S = "0"+S
G = {i:[] for i in range(1,N+1)}
for _ in range(M):
    u,v = map(int,input().split())
    G[u].append(v)
    G[v].append(u)
A = [0 for _ in range(N+1)]
for i in range(1,N+1):
    if S[i]=="P":
        A[i]=1
        for j in G[i]:
            if S[j]=="D":
                A[j] = (A[j]+A[i])%p
for i in range(1,N+1):
    if S[i]=="D":
        for j in G[i]:
            if S[j]=="C":
                A[j] = (A[j]+A[i])%p
for i in range(1,N+1):
    if S[i]=="C":
        for j in G[i]:
            if S[j]=="A":
                A[j] = (A[j]+A[i])%p
cnt = 0
for i in range(1,N+1):
    if S[i]=="A":
        cnt = (cnt+A[i])%p
print(cnt)