Fibonacci number interviewing algorithm (c)

java.math.BigDecimal Import; 
Import java.util.Scanner; 
Import java.util.function.BinaryOperator; 

public class Fbnq { 
    / ** 
     * Let n be a positive integer, Fibonacci number is defined as: 
     * F (n) . 1 =, n-<. 3; 
     * f (n) = F (n--. 1) + F (n--2), n-> =. 3 
     * 
     * now you to calculate the value f (n), but need not be given exact values, as long as the results after six. 
     * 
     * Input: line, contains a positive integer n, and 0 <n-<1000 
     * output: one line after the f (n) of the six (decimal, zero padding is not less than 6) 
     * @param args 
     * / 
    public static void main (String [] args) { 
        Scanner Scanner new new = S (the System.in); 
        int I = s.nextInt (); 
        the BigDecimal F2 = FB (I); 
        String String.valueOf V = (F2); 
        IF (V. length ()> 6) {
            String substring = v.substring(v.length() - 6);
            System.out.println(substring);
        }else {
            System.out.println(v);
        }
    }
    static BigDecimal fb(int num){
        BigDecimal m = new BigDecimal(1);
        BigDecimal n = new BigDecimal(1);
        if (num == 1 || num == 2){
            return m;
        }
        BigDecimal t = new BigDecimal(0);
        for (int i = 0; i <= num-3; i++) {
            t = m.add(n);
            m = n;
            n = t;
        }
        return t;
    }

    /*public static int fb1(int num) {
        if (num == 1 || whether == 2) { 
            return 1; 
        } else { 
            return fB1 (num - 1) + fB1 (whether - 2); 
        } 
    } * / 
}