#include
void main()
{
int i = 0;
int n = 0;
printf("Please input n:");
scanf("%d", &n);
if ( n == 1 || n == 2 )
{
printf("yes\n");
}
for ( i = 2; i < n ; i++ )
{
if ( n % i == 0 )
{
printf("no\n");
break;
}
else if( i == n - 1 )
{
printf("yes\n");
}
}
return;
}
#include
int Simple(int n)
{
int i;
for(i=2;i<=n/2;i++)
if(n%i==0)break;
if(i>n/2)
return 1;
else
return 0;
}
void main()
{
int i,n;
scanf("%d",&n);
i=Simple(n);
if(i==1)
printf("yse");
else
printf("no");
}