Java program to insert an array at a particular position

import java.io.*;
class Insrt
{
public static void main(String args[])
{
int a[=new int[20];
{
int p,i,j,pos,n,num;
DataInputStream r=new DataInputStream(System.in);
System.out.println("Enter the range");
n=Integer.parseInt(r.readLine());
System.out.println("Enter the array");
for(i=0;i<n;i++)
a[i]=Integer.parseInt(r.readLine());
System.out.println("Enter the position to insert");
pos=Integer.parseInt(r.readLine());
System.out.printl("Enter the no");
num=Integer.parseInt(r.readLine());
System.out.println("Array after insertion is");
for(i=n-1;i>pos-1;i--)
{
a[i=1]=a[i];
}
a[pos-1]=num;
for(i=1;i<=n;i++)
System.out.println(a[i]);
}
}
}