#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<iostream>

using namespace std;

struct BigInteger {
    int len , num[2000];
    BigInteger() {
        memset( num , 0 , sizeof num );
        len = 0;
    }
    friend BigInteger operator + ( const BigInteger &a , const BigInteger &b ) {
        BigInteger c;
        c.len = max( a.len , b.len );
        for( int i = 0 ; i < c.len ; i++ )
            c.num[i] = a.num[i]+b.num[i];
        for( int i = 0 ; i < c.len ; i++ ){
            c.num[i+1] += c.num[i]/10;
            c.num[i] %= 10;
        }
        if( c.num[c.len] )
            c.len++;
        return c;
    }
    void output(){
        for( int i = len-1 ; i >= 0 ; i-- )
            cout << num[i];
        cout << endl;
    }
} f[300];

int n;

void init(){
    BigInteger one;
    one.len = one.num[0] = 1;
    f[0] = f[1] = one;
    for( int i = 2 ; i <= 200 ; i++ )
        f[i] = f[i-1]+f[i-2];
}

int main(){
    init();
    while( cin >> n )
        f[n].output();
    return 0;
}