Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()
	n := nint()
	r := fibonacci(n)
	fmt.Println(r)
}

func fibonacci(n int) int{
	if n == 0 || n == 1{
		return 1
	}else{
		fiList := make([]int, n+1)
		fiList[0] = 1
		fiList[1] = 1
		for i:=2; i<n+1; i++{
			fiList[i] = fiList[i-1] + fiList[i-2]
		}
		return fiList[n]

	}

}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

C++: using namespace std;

int dp[44];

int fib(int n) {
	if (dp[n] != -1)return dp[n];
	int res;

	if (n == 0 || n == 1) {
		res = 1;
	}
	else {
		res = fib(n - 1) + fib(n - 2);
	}

	dp[n] = res;
	return res;
}

int main() {
	for (int i = 0; i < 44; i++) {
		dp[i] = -1;
	}
	int n;
	cin >> n;
	cout << fib(n);

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for (int i = 0; i < n; i++)
typedef long long ll;
// Welcome to my source code!

int F[45] = {};

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

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

C++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_10_A: Fibonacci Number

#include <algorithm>
#include <cstdio>

#define NDEBUG
#include <cassert>

class Fibonnacci {
  static const unsigned int N = 44u;
  unsigned int n_;
  unsigned long* f_;

public:
  Fibonnacci(unsigned int n = N) : n_(std::max(1u, n))
  {
    f_ = new unsigned long[n_+1];
    f_[0] = f_[1] = 1;
    for (auto i = 2u; i <= n_; ++i) {
      f_[i] = f_[i-1] + f_[i-2];
    }
  }

  ~Fibonnacci() { delete[] f_; }
  
  unsigned long operator () (unsigned int n) const
  {
    assert(n <= n_);
    return f_[n];
  }
};

int main()
{
  unsigned int n;
  std::scanf("%u", &n);
  Fibonnacci fib;
  std::printf("%lu\n", fib(n));
}

// eof

C++: #include <cstdint>

using namespace std;

#define MEMO_SIZE 45
int64_t memo[MEMO_SIZE];

void fib_init()
{
  for (uint32_t i = 0; i < MEMO_SIZE; i++) {
    memo[i] = -1;
  }
}

uint32_t fib(uint32_t i)
{
  if (i == 0) {
    return memo[0] = 1;
  } else if (i == 1) {
    return memo[1] = 1;
  } else {
    if (memo[i] != -1)
      return memo[i];
    else {
      return memo[i] = fib(i - 1) + fib(i - 2);
    }
  }
}

#include <iostream>

int32_t main()
{
  fib_init();
  uint32_t i;
  cin >> i;
  cout << fib(i) << endl;
  return 0;
}

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

unordered_map<int,int> memo;
constexpr int fib(int n){
    if(n<2) return 1;
    if (not memo.count(n)) memo[n] = fib(n-1)+fib(n-2);
    return memo[n];

}

int main(void){cin.tie(0);ios::sync_with_stdio(false);
    int n; cin>>n;
    cout<<fib(n);
}

C++: #include <bits/stdc++.h>
using namespace std;

int main() {
    int n ;
    cin >> n;
    int a[n+1];
    a[0] = 1;
    a[1] = 1;
    for (int i = 2; i <= n; i++) {
        a[i] = a[i-1] + a[i-2];
    }
    
    cout << a[n] << endl;
    
    return 0;
    
}

C++: #include <bits/stdc++.h>

using namespace std;

#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)

#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))

typedef long long ll;
typedef pair<int, int> PII;

const double EPS = 1e-10;

const int M = 2;
int a[M][M], b[M][M], w[M][M];
int n;

//???????£?
//recursive function(with/without memo)

void multiple_mat_ab_b() {
  int i, j, k;
  memset(w, 0, sizeof(w));
  for (i=0; i<M; i++)
    for (j=0; j<M; j++)
      for (k=0; k<M; k++)
        w[i][j] += a[i][k]*b[k][j];

  for (i=0; i<M; i++)
    for (j=0; j<M; j++)
        b[i][j] = w[i][j];
}

void multiple_mat_aa_a() {
  int i, j, k;
  memset(w, 0, sizeof(w));
  for (i=0; i<M; i++)
    for (j=0; j<M; j++)
      for (k=0; k<M; k++)
        w[i][j] += a[i][k]*a[k][j];

  for (i=0; i<M; i++)
    for (j=0; j<M; j++)
        a[i][j] = w[i][j];
}

void pow_mat_a(int k) {
  a[0][0] = a[0][1] = a[1][0] = 1;
  a[1][1] = 0;

  b[0][0] = b[1][1] = 1;
  b[0][1] = b[1][0] = 0;

  while (k) {
    if (k & 1) multiple_mat_ab_b();
    multiple_mat_aa_a();
    k >>= 1;
  }
}

int main() {
  scanf("%d ", &n);
  pow_mat_a(n);
  printf("%d\n", b[1][0]+b[1][1]);

	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;

  return 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>

using namespace std;

int fibdp[50];

int fib(int n){
	if(n == 1 || n == 0){
		return 1;
	}
	if (fibdp[n] != 0){
		return fibdp[n];
	}
	return fibdp[n] = fib(n - 1) + fib(n - 2);
}
int main(){
	int n;

	cin >> n;

	cout << fib(n) << endl;
}

C++: #include <iostream>
#include <cstdio>
#include <climits>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <string>

#define MAX 200000
#define INFTY 1<<30

using namespace std;

int main()
{
  int n; cin >> n;
  int F[MAX];
  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 <stdio.h>

int main() {
    int n;
    scanf("%d", &n);
    int F[50];
    F[0] = 1;
    F[1] = 1;
    for(int i=2; i<50; i++) F[i] = F[i-2] + F[i-1];
    
    printf("%d\n", F[n-1]);
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX_N 10000
int dp[MAX_N];
int fib(int n){
    dp[0]=1;
    dp[1]=1;
    for(int i=2;i<=n;i++){
        dp[i]=dp[i-1]+dp[i-2];
    }
    return dp[n];
}
int main(){
    int n;
    cin>>n;
    int ans=fib(n);
    cout<<ans<<endl;
    return 0;
}

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

int makeFibonacci(int n) {
	int a[100];
	a[0] = 1;
	a[1] = 1;

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

	return a[n-1];
}


int main(void) {
	int n;
	cin >> n;

	int ans = makeFibonacci(n);

	cout << ans << endl;

	return 0;

}

C++: #include<iostream>
using namespace std;
int main() {
	int F[45];
	F[0] = 1;
	F[1] = 1;
	int n;
	cin >> n;
	for (int 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;

int main(){
   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;
}