python这个怎么改

def isprime(n):
count=0
for i in range(2,n):
if n%i==0:
break
else:
count+=1
return count

def f(n):
ls=[]
s=0
for i in range(2,n+1):
k=isprime(i)
if k>0:
ls.append(i)
print(ls)
for i in ls[-1:-11]:
s=s+i
return s

p=int(input())

print(f(p))

有啥问题？
建议代码用插入代码块功能贴一下