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

	public class fib_i {
		
		public static void main(String[] args) throws IOException {
			int n;
			long fibVal;
			BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
			String s;
			
			System.out.println("Welcome to the iterative Fibonacci program.");
			System.out.println();
			System.out.print("Enter n: ");
			s = stdin.readLine();
			n = Integer.parseInt(s);
			while (n >= 0) {
				fibVal = fibFun(n);
				System.out.println("Fibonacci of " + n + " = " + fibVal);
				System.out.println();
				System.out.print("Enter n: ");
				s = stdin.readLine();
				n = Integer.parseInt(s);
			}
		}
			
		public static long fibFun(int n) {
			long[] fibArr = new long [101];
			
			fibArr[0] = 0;
			fibArr[1] = 1;
			for (int i=2; i<=n; ++i)
				fibArr[i] = fibArr[i-1] + fibArr[i-2];
			return fibArr[n];
		}
	}