View Code of Problem 23

#include<stdio.h>
int main(){
	int n;
	while(scanf("%d",&n)!=EOF){
		if(n==0){
			break;
		}
		int a[91];
		a[0]=1;
		a[1]=2;
		a[2]=3;
		for(int i=2;i<91;i++){
			a[i]=a[i-1]+a[i-2];
		}
		printf("%d\n",a[n-1]);
		
	} 
	
	
	return 0;
}