# your code goes here
a=[1 for i in range(0,1001)]
for i in range(2,1001):
k=2
while i*k<=1000:
a[i*k]=0
k+=1
result=0
for i in range(2,1001):
if a[i]==1:
result+=i
print(result)
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCmE9WzEgZm9yIGkgaW4gcmFuZ2UoMCwxMDAxKV0KZm9yIGkgaW4gcmFuZ2UoMiwxMDAxKToKICAgIGs9MgogICAgd2hpbGUgaSprPD0xMDAwOgogICAgICAgIGFbaSprXT0wCiAgICAgICAgays9MQpyZXN1bHQ9MApmb3IgaSBpbiByYW5nZSgyLDEwMDEpOgogICAgaWYgYVtpXT09MToKICAgICAgICByZXN1bHQrPWkKcHJpbnQocmVzdWx0KQ==