(URI) Esfera - Solução

import java.io.*;
import java.util.*;

class Main  {
    public static void main(String[] args) throws NumberFormatException, IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       
        int raio = leitor(br);
       
        double volume = (4.0/3.0) * 3.14159 * Math.pow(raio, 3);
       
        System.out.print("VOLUME = ");
        System.out.printf("%.3f\n", volume);
    }
   
    static int leitor(BufferedReader br) throws NumberFormatException, IOException {
       int n;
       int resp = 0;

       while (true) {
           n = br.read();
           if (n >= '0' && n <= '9') break;

       }
       while (true) {
           resp = resp*10 + n-'0';
           n = br.read();
           if (n < '0' || n > '9') break;
       }

       return resp;
    }
}