Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	dp := make([]int, N+1)
	dp[0] = 1
	dp[1] = 1
	for i := 2; i <= N; i++ {
		dp[i] = dp[i-1] + dp[i-2]
	}

	fmt.Fprintln(wtr, dp[N])
	wtr.Flush()
}

C++: #include <bits/stdc++.h>
#include <cassert>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
struct Edge
{
  int to;
  int weight;
  Edge(int t, int w) : to(t), weight(w) {}
};
//using Graph = vector<vector<Edge>>;
using Graph = vector<vector<int>>;

const long long INF = 1LL << 60;
const int INT_INF = 1000000000;
const double PI = acos(-1.0);

int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx[8] = {-1, -1, -1, 0, 0, 1, 1, 1}, dy[8] = {-1, 0, 1, 1, -1, 1, 0, -1};

int main()
{
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  int F[50];
  F[0] = F[1] = 1;
  for (int i = 2; i <= n; i++)
    F[i] = F[i - 1] + F[i - 2];
  cout << F[n] << endl;
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string>
#include <vector>
#include <cctype>
#include <cstdio>
#include <iomanip>
#include <functional>
#include <stack>
#define PI 3.1415926535
#define INF 114514810
#define FOR(i, r, n) for(int i=(r); i<(n); i++) 
#define REP(i, n) FOR(i, (0), n)

using namespace std;

int n;

int fib(int k){
	if (k == 0 || k == 1) return 1;
	return fib(k - 1) + fib(k - 2);
}

int main(){
	cin >> n;
	cout << fib(n) << endl;
}

C++: #include <iostream>
using namespace std;


int fibonacci(int n)
{
    if (n == 0 || n == 1)
    {
        return 1;
    }
    else
    {
        return fibonacci(n-1) + fibonacci(n-2);
    }
}

int main()
{
    int C;

    cin >> C;

    cout << fibonacci(C) << endl;

    return 0;
}

C++: #include<iostream>

using namespace std;
int fib(int n);

int memo[45];
int main(){
  int n;
  cin >> n;
  cout << fib(n) << endl;
  retrun 0;
}

int fib(int n){
  
  if(n==0){
    return 1;
  }else if(n==1){
    return 1;
  }
  else if(memo[n] !=0){
    return memo[n];
  }else{
    return memo[n]=fib(n-1]+fib(n-2);
  }
  
}

C++: #include <bits/stdc++.h>
using namespace std;
#define ul unsigned long long
#define ll long long

int main() {
  ul n,f[45];
  cin>>n;
  f[0]=1;
  f[1]=1;
  for (size_t i = 2; i <= n; i++)
  {
    f[i]=f[i-1]+f[i-2];
  }
  
  cout<<f[n]<<endl;

  return 0;
}

C++: #include <iostream>
using namespace std;
#define MAX 44

int main(){
  int fibo[MAX];
  int n;
  fibo[0] = fibo[1] = 1;
  for(int i = 2; i < MAX; i++)
    fibo[i] = fibo[i-1] + fibo[i-2];

  cin >> n;
  cout << fibo[n-1] << endl;
}

C++: #include<stdio.h>
#include<algorithm>
#include<string.h>
using namespace std;
#define NIL -2000000001
#define MAX 2000

int A[MAX];
int n = 0;

int fib(int num) {
  if (num == 0 || num == 1) {
    return A[num];
  } else {
    return fib(num-1)+fib(num-2);
  }
}

int main() {
  int num;
  A[0] = 1;
  A[1] = 1;
  scanf("%d", &num);
  printf("%d\n", fib(num));
  return 0;
}

C++: #include<iostream>

using namespace std;
int fib(int n);

int memo[45];
int main(){
  int n;
  cin >> n;
  cout << fib(n) << endl;
  retrun 0;
}

int fib(int n){
  
  if(n == 0){
    return 1;
  }else if(n == 1){
    return 1;
  }
  else if(memo[n] != 0){
    return memo[n];
  }else{
    return memo[n]= fib(n-1) + fib(n-2);
  }
  
}

C++: #include <iostream>
#include <cstdio>
using namespace std;

const int Max = 45;

int FibArray[Max];

int fib(int n){
    if(n == 0) return 1;
    if(n == 1) return 1;
    
    if(FibArray[n] != 0) return FibArray[n];
    else{
        int val = fib(n-1) + fib(n-2);
        FibArray[n] = val;
        return val;
    }
}

int main(){
    int index;
    scanf("%d", &index);

    printf("%d\n", fib(index));
    return 0;
}

C++: #include <iostream>

using namespace std;

int fib(int n);

int main() {
int n;
int dfep[45];

dp[0] = 1;
dp[1] = 1;

cin >> n;

for(int i = 2; i <= n; i++) {
dp[i] = dp[i-1] + dp[i-2];
}

cout << dp[n] << endl;
return 0;
}

C++: #include <iostream>
using namespace std;
int main(void){

	int n;

	cin >> n;

	int f[44];
	f[0] = 1; f[1] = 1;

	for (int i = 2; i <= n; i++){
		f[i] = f[i - 1] + f[i - 2];
	}

	cout << f[n] << endl;

}

C++: #include <iostream>

using namespace std;

#define INF -1

int dp[45];

int main()
{
	for(int i = 0; i < 45; i++) { dp[i] = INF; }

	int n;

	cin >> n;

	dp[0] = 1;
	dp[1] = 1;

	for(int i = 2; i <= n; i++)
	{
		dp[i] = dp[i - 1] + dp[i - 2];
	}

	cout << dp[n] << endl;

	getchar();
	getchar();
	return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;
int A[50];
int fib(int n){
	if(A[n]) return A[n];
	else if(n==1 || n==0) A[n]=1;
	else A[n]=fib(n-1)+fib(n-2);
	return A[n];
}

int main (){
	int n;
	cin>>n;
	cout<<fib(n)<<endl;
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define vv(type, c, m, n, i) vector<vector<type>> c(m, vector<type>(n, i));
#define rep(i,a,n) for(int i=(a), i##_len=(n); i<i##_len; ++i)
#define rrep(i,a,n) for(int i=(a), i##_len=(n); i>i##_len; --i)
#define len(x) ((int)(x).size())
#define mp make_pair
#define eb emplace_back
typedef long long ll;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;
typedef vector<bool> vb;
int main() {
	int n; cin >> n;
	vi v(50, 0);
	v[0] = v[1] = 1;
	rep(i, 2, n + 1) {
		v[i] = v[i - 2] + v[i - 1];
	}
	P(v[n]);
	return 0;
}

C++: #include<iostream>
#include<string>
#include <vector>
#include <stack>
#include <queue>
#include <list>
#include <algorithm>
#include <cstdlib>
using namespace std;
int ctoi(char c) {
	switch (c) {
	case '0': return 0;
	case '1': return 1;
	case '2': return 2;
	case '3': return 3;
	case '4': return 4;
	case '5': return 5;
	case '6': return 6;
	case '7': return 7;
	case '8': return 8;
	case '9': return 9;
	default: return 0;
	}
}

int main() {
	int N;
	cin >> N;
	vector<int> F(50);
	F.at(0) = F.at(1) = 1;
	for (int i = 2; i <= N; i++) {
		F.at(i) = F.at(i - 1) + F.at(i - 2);
	}
	cout << F.at(N) << endl;
}