View Code of Problem 23

#include<stdio.h>
int main()
{
	int i,n;
	while(scanf("%d",&n)!=EOF&&n>0)
	{
		long a[90];
		a[0]=1,a[1]=2;
		for(i=2;i<n;i++)
			a[i]=a[i-1]+a[i-2];
		printf("%ld\n",a[n-1]);
	}
	return 0;
}