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

int fib(int n);
int main(){
  int n;
  int dp[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(){
    int n;
    int *fib;
    cin>>n;
    fib=new int[n];
    fib[0]=fib[1]=1;
    for(int i=2;i<=n;i++){
        fib[i]=fib[i-1]+fib[i-2];
    }
    cout<<fib[n]<<endl;
}

C++: #include"iostream"
using namespace std;
int main()
{
	int n;
	cin >> n;
	int dp[50];
	int i;
	dp[0] = dp[1] = 1;
	for (i = 2; i < 50; ++i)
		dp[i] = dp[i - 1] + dp[i - 2];
	cout << dp[n] << endl;
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep2(i,n) for(int i=1;i<=(n);i++)
#define rep3(i,i0,n) for(int i=i0;i<(n);i++)
#define pb push_back
#define mod 1000000007
const ll INF = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}
#define all(x) x.begin(), x.end()
#define mp make_pair
bool compare(pair<int, int> a, pair<int, int> b) {
    if(a.first != b.first){
        return a.first < b.first;
        
    }else{
        return a.second < b.second;
    }
}


bool In_map(ll y,ll x,ll h,ll w){
    if(y<0 || x<0 || y>=h || x>=w){
        return 0;
    }else{
        return 1;
    }
}
const vector<ll> dx{1,0,-1,0};
const vector<ll> dy{0,1,0,-1};
int main() {
    ll N;
    cin >> N;
    
    vector<ll> dp(N+1);
    dp[0] = 1;
    dp[1] = 1;
    rep3(i,2,N+1){
        dp[i] = dp[i-1] + dp[i-2];
    }

       
    cout << dp[N] << endl;



    return 0;
    

}

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

int main()
{
	int n,x1=1,x2=1,tmp=0;
	cin >> n;
	
	if(n==0||n==1) cout << "1";
	else{
		for(;n>2;n--){
			tmp=x1+x2;
			x1=x2;
			x2=tmp;
		}
		cout << x1 + x2;
	}
	
	return 0;
	
}

C++: #include <iostream>
using namespace std;
int main(){
    int n,a[100];
    cin>>n;
    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<stdio>
#include<stream>
using namespace std;

int fibo(int x) {
  int a;
  if ( x == 0 ) return 1;
  if ( x == 1 ) return 1;
  a = fibo(x-1) + fibo(x-2);
  return a;
}

int main() {
  int x, y;

  cin >> x;

  y = fibo(x);

  cout << y << endl;

  return 0;
}

C++: #include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <cassert>
#include <cfloat>
#include <complex>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

using namespace std;

#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define Sort(v) sort(v.begin(), v.end())
#define Reverse(v) reverse(v.begin(), v.end())
#define Lower_bound(v, x) \
  distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) \
  distance(v.begin(), upper_bound(v.begin(), v.end(), x))

using ll = long long;
using ull = unsigned long long;
using P = pair<ll, ll>;
using T = tuple<ll, ll, ll>;
using vll = vector<ll>;
using vP = vector<P>;
using vT = vector<T>;
using vvll = vector<vector<ll>>;
using vvP = vector<vector<P>>;
using dqll = deque<ll>;

ll dx[9] = {-1, 1, 0, 0, -1, -1, 1, 1, 0};
ll dy[9] = {0, 0, -1, 1, -1, 1, -1, 1, 0};

const ll INF = 1LL << 50;

const ll mod = 1e9 + 7;

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

  if (n <= 1) {
    puts("1");
    return 0;
  }

  ll fn = 2;
  ll fn1 = 1, fn2 = 1;
  rep(i, n - 2) tie(fn, fn1, fn2) = T(fn + fn1, fn, fn1);
  cout << fn << endl;

  return 0;
}

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

unsigned long long ull[45];

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

C++: #include<iostream>

using namespace std;
int fib(int n);
int memo[45];
int main() {
  int n;

  //入力
  cin >> n;

  //出力
  cout << fib(n) << endl;

  return 0;
}

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

C++: /*
 * a.cc: 
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>

using namespace std;

/* constant */

const int MAX_N = 44;

/* typedef */

/* global variables */

int fs[MAX_N + 1];

/* subroutines */

/* main */

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

  fs[0] = fs[1] = 1;

  for (int i = 2; i <= n; i++)
    fs[i] = fs[i - 1] + fs[i - 2];

  printf("%d\n", fs[n]);
  return 0;
}

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

int main()
{
	int n,x1=1,x2=1,tmp=0;
	cin >> n;
	
	if(n==0||n==1) cout << "1";
	else{
		for(;n>2;n--){
			tmp=x1+x2;
			x1=x2;
			x2=tmp;
		}
		cout << x1 + x2;
	}
	
	return 0;
	
}

C++: #include <cstdio>
#include <algorithm>
#include <utility>

using namespace std;

int main() {
    size_t n;
    scanf("%zu", &n);

    int fib[2]={1, 1};
    for (size_t i=0; i<n; ++i)
        swap(fib[0]+=fib[1], fib[1]);

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

C++: #include <iostream>

using namespace std;

#define MAX 45

int FibValue[MAX];

long long FibonacciNumber(int n)
{
	if (FibValue[n] != -1) return FibValue[n];

	if (n == 0 || n == 1)
	{
		FibValue[n] = 1;
		return FibValue[n];
	}

	FibValue[n] = FibonacciNumber(n - 1) + FibonacciNumber(n - 2);
	return FibValue[n];
}

int main()
{
	for (int i = 0; i < MAX; ++i)
		FibValue[i] = -1;
	int n; cin >> n;

	cout << FibonacciNumber(n) << endl;

	return 0;
}