Go: package main

/*
フィボナッチ数列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func fibWithMemo(n int, memo map[int]int) int {
	if n == 0 || n == 1 {
		return 1
	}
	if val, ok := memo[n]; ok {
		return val
	}
	memo[n] = fibWithMemo(n-1, memo) + fibWithMemo(n-2, memo)
	return memo[n]
}

func fib(n int) int {
	memo := make(map[int]int)
	return fibWithMemo(n, memo)
}

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	fmt.Println(fib(n))
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

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

int main()
{
	int n;
	cin >> n;
	long long fib[50];
	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<cmath>
#include<algorithm>
#include<string>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<iomanip>
#include<bitset>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
typedef pair<ll,P> P1;
typedef pair<P,P> P2;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define fi first
#define sc second
#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())

const int MAX = 510000;
const int MOD = 1000000007;

int main(){
  vector<ll> dp(MAX);
  ll N; cin >> N;
  dp[0] = 1; dp[1] = 1;
  rep(i,N){
    dp[i + 2] = dp[i] + dp[i + 1];
  }
  cout << dp[N] << endl;

}

C++: // fibonacci number.
#include<stdio.h>

int main()
{
    int n;
    int A[45];
    scanf("%d", &n);
    A[0] = 1; A[1] = 1;
    for(int i = 2; i <= n; i++) A[i] = A[i - 1] + A[i - 2];
    printf("%d\n", A[n]);
    return 0;
}

C++: #include<stdio.h>
#include<queue>
#include<algorithm>
using namespace std;
int a[100];
int main(){
int n;
a[1]=1;
a[2]=1;
scanf("%d",&n);
  for (int i=3;i<=n+1;i++)
    a[i]=a[i-1]+a[i-2];
    printf("%d\n",a[n+1]);
return 0;}

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

#define REP(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define all(x) (x).begin(),(x).end()
using ll = long long;
string char_to_string(char val) {
  return string(1, val);
}
int char_to_int(char val) {
  return val - '0';
}
template<class T> inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template<class T> inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
int vector_finder(std::vector<ll> vec, int number) {
  auto itr = std::find(vec.begin(), vec.end(), number);
  size_t index = std::distance( vec.begin(), itr );
  if (index != vec.size()) { // 発見できたとき
    return 1;
  }
  else { // 発見できなかったとき
    return 0;
  }
}

// DP
int n; 
vector<ll> dp;
ll fibo(int i) {
  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() {
  cin >> n; dp.resize(100);
  cout << fibo(n) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll n;
    cin >> n;
    n++;
    vector<ll> dp(n);
    dp[0] = 1; dp[1] = 1;
    rep(i, n - 2) {
        dp[i + 2] = dp[i] + dp[i + 1];
    }
    cout << dp[n - 1] << endl;
    return 0;
}

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 "bits/stdc++.h"

using namespace std;

int main (){
	int n;
	cin >> n;
	int a[44];
	a[0] = 1;
	a[1] = 1;
	for (int i = 2;i<=n;i++){
		a[i] = a[i - 1] + a[i - 2];
	}
	cout << a[n - 1]<<endl;

	return 0;
}

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

static const int maxn=44;

int DP[45];

int Fibonacci(int n) {
  if (n==0 or n==1) 
    return DP[n]=1;
  
  if (DP[n]!=(-1)) 
    return DP[n];
  
  return DP[n]=Fibonacci(n-1)+Fibonacci(n-2);
}
int main() {
  std::ios::sync_with_stdio(false);
  cout.tie(0);
  cin.tie(0);
  memset(DP,(-1),sizeof(DP));
  Fibonacci(maxn);
  int n;
  cin>>n;
  cout<<DP[n]<<endl;
  return 0;
}

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

int F[MAX];

int main(){
  F[0]=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;
}

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

int main(){
  int n;
  cin >> n;
  int fn[50];
  fn[0] = fn[1] = 1;
  for(int i = 2; i <= n; i++) fn[i] = fn[i - 1] + fn[i - 2];

  cout << fn[n] << end;
  }
  return 0
}

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