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 <bits/stdc++.h>
using namespace std;

long long n;
vector<long long> f;

long long calc(long long x) {
  if(f[x] != -1) return f[x];
  return f[x] = calc(x - 1) + calc(x - 2);
}

int main() {
  cin >> n;
  f.assign(n + 1, -1);
  f[0] = f[1] = 1;
  cout << calc(n) << endl;
  return 0;
}

C++: #include<iostream>
#include <string>
using namespace std;
int a,ans[46];
int main(){
	cin>>a;
	ans[0]=1,ans[1]=2;
	for(int i=0;i<a;i++){
	ans[i+2]=ans[i+1]+ans[i];}
	cout<<ans[a-1]<<endl;
		    return 0;
	}

C++: #include <iostream>
 
using namespace std;
 
typedef unsigned long long ull;
 
auto fib(ull const n) -> ull
{
    return ( n == 1 || n == 0 ) ? n : fib( n - 1 ) + fib( n - 2 );
}
 
int main()
{
    ull n;
    cin >> n;
    cout << fib( n ) << endl;
}

C++: #include<iostream>

using namespace std;

int fib(int n);

int main() {
  int n;

  //入力
  cin >> n;

  //出力
  cout << fib(n) << endl;

  return 0;
}

int fib(int n){
  int dp[1000];
  dp[0] = 1;
  dp[1] = 1;

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

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

int main(){
	
	int n[47];
	n[1]=1;n[2]=2;

	for(int i=3;i<=45;i++)
		n[i]=n[i-1]+n[i-2];

	cout<<n[44]<<endl;
	return 0;
}

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

#define INF 1e9
vector<int> memo;

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

int main(void){
  int n;
  cin >> n;
  
  memo = vector<int>(n + 1, -INF);
  memo[0] = memo[1] = 1; 
  
  cout << fib(n) << endl;
  return 0;
}

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

constexpr ll DP_MAX = 1000000;
ll dp[DP_MAX];

int main(int argc, char **argv)
{
	ll n; cin >> n;
	memset(dp, 0, sizeof dp);
	dp[0] = dp[1] = 1;
	for (ll i = 2; i <= n; ++i)
		dp[i] = dp[i-1] + dp[i-2];
	std::cout << dp[n] << std::endl;
}

C++: #include<iostream>

using namespace std;

int fib(int n);

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{
    return fib(n-1) + fib(n-2);
  }
}

C++: #include <iostream>
#include <vector>

using namespace std;

int main(){
  int n; cin >> n;
  vector<int> fib;
  fib.push_back(0); fib.push_back(1);

  for(int i=0; i<n; i++)
    fib.push_back(fib[i]+fib[i+1]);

  cout << fib.back() << endl;

  return 0;
}

C++: #include <iostream>

using namespace std;

int memo[45];

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

int main()
{
    for (int i = 0; i < 45; ++i)
        memo[i] = -1;

    int n;
    cin >> n;
    cout << fibonacchi(n) << '\n';
}

C++: #include<stdio.h>

int main()
{
	int fib1{ 1 }, fib2{ 1 }, n;

	scanf("%d", &n);
	for (int i = 1; i < n; ++i)
	{
		int tmp = fib2;
		fib2 += fib1;
		fib1 = tmp;
	}
	printf("%d\n", fib2);
	return 0;
}