Problem E: Fibonacci Numbers

A Fibonacci sequence is calculated by adding the previous two members of the sequence, with the first two members being both 1.

Input and Output 

Your task is to take numbers as input (one per line), and print the corresponding Fibonacci number.

Sample Input 

3
100

Sample Output 

2
354224848179261915075

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import java.util.Scanner;
import java.math.BigInteger;
public class Main {
	public static void main(String[] args) {
		int n;
		Scanner keyboard = new Scanner(System.in);
		BigInteger[] F = new BigInteger[5000];
		F[1] = BigInteger.valueOf(1);
		F[2] = BigInteger.valueOf(1);
		for(n = 3; n < 5000; n++) {
			F[n] = F[n-1].add(F[n-2]);
		}
		while(keyboard.hasNext()) {
			n = keyboard.nextInt();
			System.out.println(F[n]);
		}
	}
}