Pile

import java.util.ArrayList;

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author viljampa
 */
public class kilpa52 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
                // TODO code application logic here
        IO io = new IO();
        ArrayList<Integer> lista = new ArrayList();
        boolean onko = true;
        
        int montako = io.nextInt();
        for (int i = 0; i < montako; i++) {
            lista.add(io.nextInt());
        }
//        int montako = 9;
//        lista.add(2);
//        lista.add(1);
//        lista.add(1);
//        lista.add(2);
//        lista.add(7);
//        lista.add(8);
//        lista.add(9);
//        lista.add(6);
//        lista.add(5);
//        lista.add(4);
//        lista.add(3);

//        lista.add(3);
//        lista.add(2);
//        lista.add(1);
//        lista.add(4);
//        lista.add(5);
//        lista.add(6);
//        lista.add(8);
//        lista.add(9);
//        lista.add(7);
        
        
        int paal = lista.get(0);
        int apu = lista.get(0);
        
        for (int i = 1; i < montako; i++) {
            int seur = lista.get(i);
            if (paal - 1 == seur) {
                paal = seur;
                apu = seur;
            } else if (apu + 1 == seur) {
                apu = seur;
            } else if (paal < seur) {
                paal = seur;
                apu = seur;
            } else {
                onko = false;
                System.out.println(seur);
            }
        }
        
        if (onko) {
            io.println("Not a proof");
        } else {
            io.print("Cheater");
        }
        
        io.println();
//	String a = io.next(); // Lukee seuraavan välein erotellun merkkijonon.
//	int b = io.nextInt(); // Lukee seuraavan välein erotellun int-kokonaisluvun.
//	long c = io.nextLong(); // Lukee seuraavan välein erotellun long-kokonaisluvun.
//	double d = io.nextDouble(); // Lukee seuraavan välein erotellun double-liukuluvun.

        // Toimii kuten System.out.println.
//	io.println("Annoit syötteenä " + a + " " + b + " " + c + " " + d);
        io.close();
    }
    
}

Test 1

Verdict: WRONG ANSWER

Test 2

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Test 3

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Test 4

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Test 5

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Test 6

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Test 7

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Test 8

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Test 9

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Test 10

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Test 11

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Test 12

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Test 13

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Test 14

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Test 15

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Test 16

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Test 17

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Test 18

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Test 19

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Test 20

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Test 21

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Test 22

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Test 23

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Test 24

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Test 25

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Test 26

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Test 27

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Test 28

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Test 29

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Test 30

Verdict: WRONG ANSWER