readFile = open('20by20.txt','r').readlines()
z=[]
for i in range(len(readFile)):
    lst=[]
    for q in readFile[i]:
        if q.isnumeric()==False:
            continue
        if q.isnumeric()==True:
            lst.append(q)
    z.append(lst)
q=0
Matrix=[]
for j in range(len(z)):
    lst=[]
    while q<40:
        if q%2==0:
            lst.append(int(str(z[j][q])+str(z[j][q+1])))
            q+=1
        if q%2!=0:
            q+=1
    Matrix.append(lst)
    q=0

def checkMax():
    maximum=0
    for i in range(20):
        for j in range(17):
            if checkSide(i,j) > maximum:
                maximum = checkSide(i,j)
    for i in range(17):
        for j in range(17):
            if checkDown(i,j) > maximum:
                maximum = checkDown(i,j)
    for i in range(17):
        for j in range(17):
            if checkDiag(i,j) > maximum:
                maximum = checkDiag(i,j)
    for i in range(17):
        for j in range(17):
            if checkOtherDiag(i,j) > maximum:
                maximum = checkOtherDiag(i,j)
    print(maximum)

def checkDown(i,j):
    product = 1
    for x in range(4):
        product*=int(Matrix[i+x][j])
    return product

def checkSide(i,j):
    product = 1
    for x in range(4):
        product*=int(Matrix[i][j+x])
    return product

def checkDiag(i,j):
    product = 1
    for x in range(4):
        product*=int(Matrix[i+x][j+x])
    return product
def checkOtherDiag(i,j):
    product = 1
    for x in range(4):
        product*=int(Matrix[i+x][j-x])
    return product

checkMax()