n,m = map(int,input().split())
s = input()
g = [[] for _ in range(n)]
for _ in range(m):
    a,b = map(int,input().split())
    g[a-1].append(b-1)
    g[b-1].append(a-1)

from collections import defaultdict
d = {i:1 for i in range(n) if s[i]=="P"}
for B in "DCA":
    nd = defaultdict(int)
    for k,v in d.items():
        for c in g[k]:
            if s[c] == B:
                nd[c] += v
    d = nd
print(sum(d.values())%(10**9+7))