1051 숫자 정사각형

https://www.acmicpc.net/problem/1051

1051번: 숫자 정사각형

n,m = map(int,input().split())
array=[]

for i in range(n):
    array.append(list(map(int,input())))


k=min(n,m)
p=max(n,m)
check=0
for h in range(k-1,-1,-1):
    if check==1:
            break

    for i in range(n-h):
        if check==1:
            break
        
        
        for j in range(m-h):
            if array[i][j]==array[i+h][j]==array[i][j+h]==array[i+h][j+h]:
                length=h
                check+=1
                break


        
length=length+1


print(length**2)