#include<stdio.h>
int main()
{
    int x;
    scanf("%d",&x);
    if(x%3==0)
        printf("yes");
    else
        printf("no");
        return 0;
}

/**************************************************************
	Problem: 1633
	User: admin
	Language: C
	Result: Accepted
	Time:9 ms
	Memory:1144 kb
****************************************************************/