To display all union ele from two different single dimension array in java

import java.io.*;
class union
 {
     public void main()throws IOException
     {
         BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
         System.out.print("Enter the size of array1 :- ");
         int s1=Integer.parseInt(br.readLine());
         System.out.print("Enter the size of array2 :- ");
         int s2=Integer.parseInt(br.readLine());
         int a[]=new int[s1];
         int b[]=new int[s2];
         int c[]=new int[s1+s2];
         int i,j,pos1=0,pos2=0,pos3=0,f=0;
         System.out.print("Enter elements of array1 ");
         for(i=0;i<s1;i++)
         a[i]=Integer.parseInt(br.readLine());
         System.out.print("Enter elements of array2 ");
         for(i=0;i<s2;i++)
         b[i]=Integer.parseInt(br.readLine());
         for(i=0;i<s1;i++)
         {f=0;
             for(j=0;j<i;j++)
             {
                 if(a[i]==a[j])
                 {
                     f=1;
                     break;
                    }
                }
                if(f==0)
                {
                    a[pos1++]=a[i];
                    c[pos3++]=a[i];
                }
            }
         
           
          
           for(i=0;i<s2;i++)
             {f=0;
             for(j=0;j<i;j++)
             {
                 if(b[i]==b[j])
                 {
                     f=1;
                     break;
                    }
                }
                if(f==0)
                b[pos2++]=b[i];
                   
            }
          
          for(i=0;i<pos2;i++)
          {f=0;
              for(j=0;j<pos1;j++)
              {
                  if(b[i]==a[j])
                  {
                      f=1;
                      break;
                }}
                if(f==0)
                c[pos3++]=b[i];
            }
            for(i=0;i<pos3;i++)
            System.out.print(c[i]+" ");
        }
    }