└── Hello.java


/Hello.java:
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 1 | import java.util.*;
 2 | public class Hello {
 3 |     public static String removeDigits(String Nu){
 4 |         String ans="";
 5 |         for(char N:Nu.toCharArray()){
 6 |             if(N=='1'||N=='0'){
 7 |                 ans+=N;
 8 |             }
 9 |         }
10 |         return ans;//returns zero and ones only
11 |     } 
12 |     public static long decimalValue(String N){
13 |         if(N.length()<=0&&N.length()>31)   return 0;
14 |         //int num=Integer.parseInt(N);
15 |         long s=0;
16 |        // int poi=0;
17 |         // while(num>0){
18 |         //     int r=(int)num%10;
19 |         //     s=s+((int)Math.pow(2,poi)*r);
20 |         //     poi++;
21 |         //     num/=10;
22 |         // }
23 |         int l=N.length()-1;
24 |         for(char i : N.toCharArray()){
25 |             int nu=Integer.parseInt(String.valueOf(i));
26 |             s+=(long)Math.pow(2,l--)*nu;
27 |         }
28 |         return s;//returns the equivalent decimal value 
29 |     }
30 |     public static void main(String[] args) {
31 | 		//Remove digits-Except 0's and 1's and print the decimal value
32 | 		Scanner sc=new Scanner(System.in);
33 | 		String N=sc.next();
34 | 		String numExcept=removeDigits(N);
35 | 		if(numExcept.equals("")){
36 | 		    System.out.print("-1");
37 | 		    return;
38 | 		}
39 | 		long val=decimalValue(numExcept);
40 | 		System.out.print((val<=0)?"-1":val);
41 | 	}
42 | }
43 | 


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