n,m=map(int,input().split())
S='PDCA'
s='#'+input()
g=[[] for _ in range(n+1)]
for _ in range(m):
    u,v=map(int,input().split())
    if S.index(s[u])-S.index(s[v])==1:
        g[v].append(u)
    elif S.index(s[v])-S.index(s[u])==1:
        g[u].append(v)
from collections import deque
q=deque()
mod=10**9+7
ans=0
for i in range(1,n+1):
    if s[i]=='P' and len(g[i])>0:
        q.append((i,1))
while q:
    now,cnt=q.popleft()
    if cnt==4:
        ans+=1
        ans%=mod
        continue
    for to in g[now]:
        q.append((to,cnt+1))
print(ans)