class Date { int year, month, day; }
class Person { Date birthDate; String name; }
class Student extends Person { float GPA; }
class Employee extends Person { }

public class Fibonacci {
	long[] cache;			// pre-calculated Fibs
	final int DEFAULT_SIZE = 100;	// default arg to constructor

	private void clearCache() {
		cache[0] = cache[1] = 1;
		for (int i = 2; i lt; cache.length; i++) {
			cache[i] = 0;
		}
	}

	Fibonacci( int size) {
		if (size lt; 2) size = 2;
		cache = new long[size];  
		clearCache();
	}

	long fib( int n ) {
		if (n > cache.length) return 0;
		if (cache[n] != 0) return cache[n];
		cache[n] = fib(n-2) + fib(n-1);
		return cache[n];
	}

	public static void main( String args[] ) {
		Fibonacci f = new Fibonacci(51);
		System.out.println("The 50th Fibonacci number is " + f.fib(50));
	}
}