#include<stdio.h>
#include<conio.h>
#include<math.h>

int nguyento(int n)

{
		int i;
		for (i=2;i<=sqrt(n);i++)
		if(n%i==0) return 0;
		return 1;

}


void main()
{
		int b,a,i;
		printf("\n Nhap a=");
		scanf("%d",&a);

		while (a!=0)

		{
		
		b=a%10;
		a=a/10;
		
		if(nguyento(b))

			printf("%d la so nguyen to",b);//neu nhap 123456 in ra 1,2,3,5 la so nguyen to thi cau lenh in la the nao?
		
		}

}

#include<stdio.h>
void main(){
  int a,b,c=0;
  printf("Nhap a=");
  scanf("%d",&a);
  while (a!=0){
	 b=a%10;
	 a=a/10;
	 if(b==1||b==2||b==3||b==5||b==7){
		if(c)printf(", "); else c=1;
		printf("%d",b);
	 }
  }
  if(c)printf(" la cac so nguyen to");
  //else printf("khong co so nao la so nguyen to");
}

int isPrime(int number)

{

   int count;

   double s;



   /* Every even number is not prime */

   if (number % 2 == 0) return FALSE;



   /* check every odd number up to the square root of the number */

   s = sqrt(number);

   for (count=3; count<=s; count+=2)

   {

      if (number % count == 0) return FALSE;

   }

   return TRUE;

}

#include<conio.h>
 #include<math.h>
 
 int nguyento(int n)
 
 {
 		int i;
 		for (i=2;i<=sqrt(n);i++)
 		if(n%i==0) 
		return 0;
 		return 1;
 
 }
 
 
 void main()
 {
 		int b,a,i;
 		printf("\n Nhap a=");
 		scanf("%d",&a); 
 		while (a!=0) 
 		{
  		b=a%10;
 		a=a/10;
 		if(nguyento(b))
 		printf("%d ",b);//neu nhap 123456 in ra 1,2,3,5 la so nguyen to thi cau lenh in la the nao?
  		}
		printf("la so nguyen to");
		getch();
  }