Build a pile of Cubes

cubes.java

public class ASum {
  
  public static long findNb(long m) {
    long total = 0;
    long n = 0;
    for (n = 1; total < m; n++) {
      total += (long) Math.pow(n, 3);
    }
    return total == m ? n - 1 : -1;
  }  
}