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 <functional>
#include <iostream>
#include <vector>

using namespace std;

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

    vector<int> memo(n + 1, -1);
    function<int(int)> f = [&memo, &f](int nn) -> int {
        if (memo[nn] != -1) {
            return memo[nn];
        }
        else if (nn == 0) {
            memo[nn] = 1;
        }
        else if (nn == 1) {
            memo[nn] = 1;
        }
        else {
            memo[nn] = f(nn - 1) + f(nn - 2);
        }
        return memo[nn];
    };

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

C++: #include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i < (n); ++i)
using namespace std;
typedef long long ll;

map<int, ll> memo;

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

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    memo[1] = 1;
    memo[0] = 1;
    cout << fib(n) << endl;

    return 0;
}

C++: #include <iostream>

using namespace std;

long long F[50];

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

int main() {
  int n;
  cin >> n;
  for (int i = 0; i < 50; i++) {
    F[i] = -1;
  }
  cout << fib(n) << endl;
}

C++: #include<iostream>
using namespace std;
int main(){
    int n,fib[45];
    cin>>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;
    return 0;
}

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

int main(int argc,char* argv[]){
  int a=1,b=1,x,n;
  cin>>n;
  if(n==1)
    cout<<1<<endl;
  else{
    for(int i=2;i<=n;i++){
      x=a+b;
      a=b;
      b=x;
    }
    cout<<x<<endl;
  }
  return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
  int n,dp[45]={1,1};
  cin >> n;
  for(int i = 2 ; i <= n ; i++ ) dp[i] = dp[i-1] + dp[i-2];
  cout << dp[n] << endl;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define mod 1000000007
#define MAX 50

ll fib(int n);

ll dp[MAX];

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

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

    dp[n] = fib(n-1) + fib(n-2);
    return dp[n];

}

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

int result[44];

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

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

C++: #include<stdio.h>

int fib(int);

int main()
{
  int a,n;

  scanf("%d",&n);

  a = fib(n);
  printf("%d\n",a);

  return 0;
}

int fib(int n){

  int a;
  
  if(n==0 || n==1){
    return 1;
  }

  a = fib(n-1)+fib(n-2);

  return a;
}