#include<iostream>
using namespace std;
int main(){//相当于用递推法求斐波那契数列
int n;
int counter[91];
counter[0] = 0;
counter[1] = 1;
counter[2] = 2;
for(int i=3;i<=90;i++){
counter[i] = counter[i-1]+counter[i-2];
}
while(cin>>n){
cout<<counter[n]<<endl;
}
return 0;
}

京公网安备 11010502036488号