/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.concurrent.ThreadLocalRandom;

class Ideone {
    public static void main(String[] args) {
        int ok = 0;
        int target = 1100; //цель
        
        for(int k = 0; k < 100; k++) {
            int balance = 1000; //текущий баланс
            int i = 0;
            int reward = 1; // начальная ставка
            while (balance > 0 && balance <= target && reward <= balance) {
                i++;
                int rnd = randomRange(1, 99);
                if (rnd >= 51) {
                    balance -= reward;
                    reward *= 2;
                } else if (rnd <= 49) {
                    balance += reward;
                    reward = 1;
                }
 
            }
            if(balance >= target) {
                ok++;
            }
        }
        System.out.print("chance: " + ok);
    }
       
    public static int randomRange(int min, int max) {
        return ThreadLocalRandom.current().nextInt(min, max + 1);
    }
}