View Code of Problem 23

#include<bits/stdc++.h>
using namespace std;
int main() {
	long long int M, arr[100];
	while(cin>>M) {
		if(M==0 || M>90) break;
		if(M==1) arr[1]=1;
		else if(M==2) arr[2]=2;
		else {
			for(int i=3; i<=M; i++) arr[i]=arr[i-2]+arr[i-1];
		}
		cout<<arr[M]<<endl;
	}
}