N,M = map(int,input().split())
V= list(map(int,input().split()))
S = []
for _ in range(N):
    S.append(list(map(lambda x:x == 'o',list(input()))))
memo = set()
ans = 0
while len(memo) < N:
    cum = [0 for _ in range(M)]
    for i in range(N):
        if i in memo:
            continue
        for m in range(M):
            if S[i][m]:
                cum[m] += V[i]
    for m in range(M):
        if cum[m] == max(cum):
            ans += cum[m] ** 2
            for i in range(N):
                if S[i][m]:
                    memo.add(i) 
            break
print(ans)