#include <stdio.h>
 
int main()
{
    int num;
    int sum=0;//因子之和
    scanf("%d",&num);
    int i;
    for(i=1; i<=num/2; i++)
    {
        if(num%i==0)
            sum+=i;
    }
    if(sum==num)
        printf("yes\n");
    else
        printf("no\n");
    return 0;
}
/**************************************************************
	Problem: 1859
	User: admin
	Language: C
	Result: Accepted
	Time:103 ms
	Memory:1144 kb
****************************************************************/