It says Python indentation error, but I don't know what's wrong.

col, row = map(int,input().split())
x = [-1, 0, 1, 1]
y = [0, 1, 0, 1]
cnt = 0
mat = []
for i in range(row):
    mat.append(list(input()))

for i in range(row):
    for j in range(col):
        if(mat[i][j] == '.'):
            for k in range(4):
                if(i+x[k]<0 or i+x[k] >= col or j+y[k]<0 or j+y[k] >= row):
                    continue
                if(mat[i+x[k]][j+y[k]]=='*'):
                    cnt+=1
            mat[i][j] = cnt
            cnt = 0

print(mat)