import sys
L = list(list(map(int,s)) for s in sys.stdin.read().splitlines())
W = len(L[0]) ; H = len(L)
S=0
for i in range(H):
	for j in range(W):
		v = L[i][j]
		# look right
		r = 0
		for k in range(j+1, W):
			r += 1
			if L[i][k]>=v:
				break
		# look left
		l = 0
		for k in range(j-1,-1,-1):
			l+=1
			if L[i][k]>=v:
				break
		# look up
		u = 0
		for k in range(i-1,-1,-1):
			u+=1
			if L[k][j]>=v:
				break
		# look down
		d = 0
		for k in range(i+1,H):
			d += 1
			if L[k][j]>=v:
				break
		S = max(S,r*l*u*d)
print(S)