效果出来，哪里出错了？

ls=[int(i) for i in input().split()]
s=''
for i in range(1,len(ls)):
        index=i
        if index%2==1:
           s+='0'*ls[i]
        else:
            s+='1'*ls[i]

for i in range(ls[0]):
    print(s[i*7:(i*7)+7])