1-5-13: The Fibonacci series

Describe

The Fibonacci sequence refers to the series: the first and second numbers of the series are 1, followed by each number equal to the sum of the preceding 2 numbers.
Give a positive integer k, which asks what is the number of K in the Philippine-Fibonacci sequence.

Enter an input line containing a positive integer k. (1 <= k <= 46) Output output line containing a positive integer representing the size of the number of K in the Fibonacci sequence

Sample input

19

Sample output

4181

SOURCE 1755

#include <stdio.h>intMain () {intk,i,a1=1, a2=1, a=1; scanf ("%d",&k);  for(i=1; i<=k-2; i++) {a=a1+A2; A1=A2; A2=A; } printf ("%d", a); return 0;}

1-5-13: Fibonacci series