java

import java.io.*;

import java.text.*;

import java.lang.*;

class Input

{

public static void main (String [ ] args)

{

int a;

for(a=0;a<=20;a++)

System.out.print(a+"\t"+Math.sqrt(a)+"\n");

}}

import java.io.*;

import java.text.*;

import java.lang.*;

class Input

{

public static void main (String [ ] args)

{

int a,b,c;

for(a=0;a<=20;a++){

c=0;

for(b=1;b<=a;b++){

if((a%b)==0)

c++

}

if(c==1||c==2)

System.out.print(a+"\t Prime \n");

else

System.out.print(a+"\tNOT Prime \n");

}}}

import java.io.*;

import java.text.*;

import java.lang.*;

class Input

{

public static void main (String [ ] args) throws IOException

{

BufferedReader stdIn = new BufferedReader(new InputStreamReader (System.in));

int a,b,c;

System.out.println("enter number(1-20): ");

a = Int.parseInt(stdIn.readLine());

c=0;

for(b=1;b<=a;b++){

if((a%b)==0)

c++

}

if(c==1||c==2)

System.out.print(a+"\t Prime \n");

else

System.out.print(a+"\tNOT Prime \n");

}

}}