#include<stdio.h>
#include<math.h>
int main()
{
int i, k, m;
void prin();
prin();
while(scanf("%d",&m)!=EOF)
{
k=sqrt(m);
for(i=2;i<=k;i++)
{
if(m%i==0)
{
break;
}
}
if(i>k)
printf("%d is a sushu\n",m);
else
printf("%d is not a sushu\n",m);
prin();
}
return 0;
}
void prin()
{
printf("Please input a number:\n");
}