#include <iostream>
using namespace std;

int fibo(int n){
    if(n==1 || n==2)
        return 1;
    return fibo(n-1) + fibo(n-2);    // fibonacci series is basically sum of n-1 and n-2
}

int main() {
    int n;
    cin>>n;
    cout<<fibo(n);  // this function basically calls 2 functions 
    // in other words multiple call  
}