Py红题RE求助

为什么RE呀

l=list(input())
n=int(l[0])
t=[[0 for i in range(n+1)] for i in range(n+1)]
a=0
x,y=1,1
for i in range(2,len(l)):
    if l[i]==' ':
        continue
    for j in range(int(l[i])):
        t[y][x]+=a
        x+=1
        if x==n+1:
            x=1
            y+=1
    a=1-a
for i in range(1,n+1):
    for j in range(1,n+1):
        print(t[i][j],end='')
    print('\n',end='')

#print (t)