View Code of Problem 23

#include<iostream>

using namespace std;

int main(void){
    long long big[91],small[91];
    big[1]=1;
    small[1]=0;
    for(int i=2;i<=90;i++){
        big[i]=small[i-1]+big[i-1];
        small[i]=big[i-1];
    }
    int n;
    while(scanf("%d",&n)){
        if(n==0){
            break;
        }
        printf("%lld\n",small[n]+big[n]);
    }
}