n, m = map(int, input().split())
v = list(map(int, input().split()))
s_list = [input().strip() for _ in range(n)]

# Create list of slimes with their values and compatibility strings, sorted by value descending
slimes = sorted(zip(v, s_list), key=lambda x: (-x[0], x[1]))

# Precompute sumVj for each box j (1-based)
sumVj = [0] * (m + 1)  # sumVj[1] to sumVj[m]
for j in range(1, m + 1):
    total = 0
    for i in range(n):
        if s_list[i][j-1] == 'o':
            total += v[i]
    sumVj[j] = total

# Initialize current sum for each box (1-based)
current_sum = [0] * (m + 1)

for value, s in slimes:
    allowed = []
    for j in range(1, m + 1):
        if s[j-1] == 'o':
            allowed.append(j)
    # Find the maximum current sum among allowed boxes
    max_cs = max(current_sum[j] for j in allowed)
    # Collect all boxes that have this maximum current sum
    candidates = [j for j in allowed if current_sum[j] == max_cs]
    # Choose the candidate with the highest sumVj
    selected = max(candidates, key=lambda x: sumVj[x])
    current_sum[selected] += value

# Calculate the total sum of squares
total = sum(s * s for s in current_sum)
print(total)