View Code of Problem 23

#include<stdio.h>
int main()
{

    int i;
    int n;
    long int a[100]={1,2,3};
    for(i=3;i<90;i++){
            a[i]=a[i-1]+a[i-2];
        }
        while(scanf("%d",&n)!=EOF){
            if(n==0){
                break;
            }
            else{
                printf("%ld\n",a[n-1]);
            }
        }


}