Modify first phone number and saved it android -

i want retrieve first phone number using code below, add 0 in front of number , saved phone number. new , , code below open contact list, user select phone number , phone number displayed toast. however, want first phone number in contact list 0 in front , saved. know not far solution while trying, faster if help. thanks.

public class mainactivity extends activity {

       public static final int pick_contact    = 1;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          // opens activity. note  intent.action_get_content         // , intent.settype         ((button)findviewbyid(r.id.btn_contacts)).setonclicklistener( new onclicklistener() {             @override             public void onclick(view v) {                 // user bod suggests using intent.action_pick instead of .action_get_content avoid chooser                 intent intent = new intent(intent.action_get_content);                 // bod con't: content_type instead of content_item_type                 intent.settype(contactscontract.commondatakinds.phone.content_item_type);                 startactivityforresult(intent, 1);                             }         });     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.activity_main, menu);         return true;     }       @override     protected void onactivityresult(int requestcode, int resultcode, intent data) {         if (data != null) {             uri uri = data.getdata();              if (uri != null) {                 cursor c = null;                 try {                     c = getcontentresolver().query(uri, new string[]{                                  contactscontract.commondatakinds.phone.number,                                   contactscontract.commondatakinds.phone.type },                             null, null, null);                      if (c != null && c.movetofirst()) {                         string number = c.getstring(0);                         int type = c.getint(1);                         showselectednumber(type, number);                     }                 } {                     if (c != null) {                         c.close();                     }                 }             }         }     }      public void showselectednumber(int type, string number) {         toast.maketext(this, type + ": " + number, toast.length_long).show();           } }