> I write this code in Java but i get runtime error, waths wrong
> 
> import java.io.BufferedReader;
> import java.io.IOException;
> import java.io.InputStreamReader;
> import java.util.ArrayList;
> import java.util.Collections;
> 
> 
> public class Main {
> 	static class Telefono implements Comparable<Telefono> {
> 		int reps = 1, number;
> 
> 		public Telefono(int a) {
> 			this.number = a;
> 		}
> 
> 		public int compareTo(Telefono obj) {
> 			return this.number - obj.number;
> 		}
> 
> 		@Override
> 		public boolean equals(Object arg0) {
> 
> 			return ((Telefono) (arg0)).number == this.number;
> 		}
> 
> 	}
> 
> 	static int pFormat(String a) {
> 		a = a.replaceAll(" ", "").replaceAll("-", "");
> 		a = a.replaceAll("[ABC]", "2");
> 		a = a.replaceAll("[DEF]", "3");
> 		a = a.replaceAll("[GHI]", "4");
> 		a = a.replaceAll("[JKL]", "5");
> 		a = a.replaceAll("[MNO]", "6");
> 		a = a.replaceAll("[PRS]", "7");
> 		a = a.replaceAll("[TUV]", "8");
> 		a = a.replaceAll("[WXY]", "9");
> 		return Integer.parseInt(a);
> 	}
> 
> 	public static void main(String[] args) throws IOException {
> 		BufferedReader lc = new BufferedReader(new InputStreamReader(System.in));
> 		ArrayList<Telefono> tels = new ArrayList<Telefono>(100000);
> 		for (int i = Integer.parseInt(lc.readLine()); i > 0; i--) {
> 			String line = lc.readLine();
> 			Telefono tep = new Telefono(pFormat(line));
> 			int num = tels.indexOf(tep);
> 			if (num!=-1)
> 				tels.get(num).reps++;
> 			else tels.add(tep);
> 		}
> 		
> 		Collections.sort(tels);
> 		boolean dupl=false;
> 		for (Telefono telefono : tels) {
> 			
> 			if(telefono.reps>1){
> 				System.out.println((telefono.number/10000)+"-"+((String)(telefono.number+"")).substring(3)+" "+telefono.reps);
> 				dupl=true;
> 			}
> 				
> 		}
> 		if (!dupl)
> 			System.out.println("No duplicates.");
> 	}
> }