python代码无法运行

这个代码为什么运行不出来啊
if name =="main":
n=0
print("请输入图中点的数量")
n=input()
juzhen=[[0 for i in range(n)] for m in range(n)]
print("请依次输入营地")
for i in range(n):
for j in range(n):
juzhen[i][j]=input()
d=[0 for m in range(n)]
p= [0 for m in range(n)]
use= [0 for m in range(n)]
for i in range(n):
d[i]=0;
use[i]=0
p[i]=0
use[0]=1
for i in range(0, n):
d[i] = juzhen[0][i]
for i in range(1, n):
k = 1
min = 100000
for j in range(0, n):
if (use[j] == 0 and d[j] < min):
min = d[j]
k = j
use[k] = 1
for w in range(0, n):
if (use[w] == 0 and min + juzhen[k][w] < d[w]):
d[w] = min + juzhen[k][w]
p[w] = k
for i in range(0, n):
print(d[i])

n=input()
改成
n=int(input())