#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a; cin>>a; switch(a) { case 1: case 3: case 5: cout<<"NO"<<endl; break; case 2: case 4: case 6: case 7: cout<<"YES"<<endl; break; default: cout<<"请输入正确数字。"; break; } return 0; }