＃include<stdio.h>
void main()
 {int prime(int);
  int n;
  printf("\input an integer:");
  scanf("%d",&n);
  if(prime(n))
    printf("\n %d is a prime.\n",n);
  else
   printf("\n %d is a primel.\n",n);
}
 int prime (int n)
  {int flag=1,i;
   for(i=2:i<n/2&&flag==1;i++)
     if(n%i==0) 
        flag=0;
  return(flag);
  }