N,M = map(int, input().split())
S = input()
E = [[] for _ in range(N)]
for _ in range(M):
    u,v = map(int, input().split())
    E[u-1].append(v-1)
    E[v-1].append(u-1)

mod = 10**9+7
PDCA = [0]*N
for i in range(N):
    if S[i] != "P":
        continue
    for v in E[i]:
        if S[v] == "D":
            PDCA[v] += 1
for i in range(N):
    if S[i] != "D":
        continue
    for v in E[i]:
        if S[v] == "C":
            PDCA[v] += PDCA[i]
for i in range(N):
    if S[i] != "C":
        continue
    for v in E[i]:
        if S[v] == "A":
            PDCA[v] += PDCA[i]
ans = 0
for i in range(N):
    if S[i] == "A":
        ans += PDCA[i]
        ans %= mod
print(ans)