p120-2-1

#include 
main()
{
 int a;
 scanf("%d",&a);
 printf("%d",hea(a));
 getchar();
 }
int hea(int a)
 {
     int b,gs=0;
     for(b=1;b<=a;b++)
     if(b%3==0 && b%10==5) gs++;
     return gs;
  }