斐波那契数列

题目描述
大家都知道斐波那契数列，现在要求输入一个整数n，请你输出斐波那契数列的第n项。
n<=39

public class Solution {
    
    public int Fibonacci(int n) {
        
        int first = 0;
        int second = 1;
        if(n == 0)
            return first;
        if(n == 1)
            return second;
        for(int i = 2; i <= n; i++) {
            
            int temp = first;
            first = second;
            second = temp + second;
        }
        return second;
    }
}