f = input().split()
n, m = int(f[0]), int(f[1])

s = input()
allSet = set()
a=[]
for i in range(m):
    f = input().split()
    l, c = int(f[0]), int(f[1])
    word = input()
    cur = set(word)
    pair = (cur, c)
    a.append(pair)
    allSet = allSet.union(cur)

s = s.replace('*', '')
a = sorted(a, key=lambda x: x[1], reverse=False)

needSet = set(s)
# print(needSet)
# print(allSet)
if not needSet.issubset(allSet):
    print(-1)
    exit(0)

k = 0
for ch in s:
    for p in a:
        if ch in p[0]:
            k += p[1]

print(k)