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<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

#define vi vector<int>
#define vl vector<long long>
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define REPD(i, n) for (int i = (int)(n-1); i >= 0; i--)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define FORD(i, a, b) for (int i = (int)(a); i >= (int)(b); i--)
#define INF 1e18
#define MOD 1e9+7

template<class T> bool chmax(T &a, const T & b) {
    if (a<b) {
        a = b;
        return true;
    }
    return false;
}

template<class T> bool chmin(T &a, const T & b) {
    if (a>b) {
        a = b;
        return true;
    }
    return false;
}

ll dp[50];

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

int main() {
    int n;
    cin >> n;
    REP(i, n+1) dp[i] = -1; 
    cout << fib(n) << endl;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <map>
#include <numeric>
#include <string>
#include <cmath>
#include <iomanip>
#include <string>
#include <queue>
#include <list>
#include <stack>

typedef long long ll;
using namespace std;
const int mod = 1000000007;

vector<ll> f(45);

int main() {

    int n; cin >> n;

    f[0] = 1; f[1] = 1;

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

    cout << f[n] << '\n';

}

C++: #include <iostream>
#include <cmath>
#include <set>
#include <string>
#include <algorithm>
#include <vector>
#include <bitset>
#include <iomanip>
#include <map>

using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;
using std::bitset;

#define rep(i,n)    for(int i=0; i<(int)n; i++)
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef vector<ll> vll;
typedef std::pair<int, int> pii;
typedef std::pair<ll, ll> pll;

template<class T>
using Graph = vector<vector<T>>;

void printFixedDouble(double d, int fix) {
    cout << std::fixed;
    cout << std::setprecision(fix) << d << endl;
}

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

    int fibonatti[45];

    fibonatti[0] = 1;
    fibonatti[1] = 1;
    for (int i = 2; i <= n; i++) {
        fibonatti[i] = fibonatti[i - 1] + fibonatti[i - 2];
    }

    cout << fibonatti[n] << endl;

}

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

using namespace std;

int fib[50];

int main()
{

    int n;

    fib[0]=fib[1]=1;

    cin>>n;

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

    cout<<fib[n]<<endl;


    return 0;
}

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

int main(){
    int n; cin >> n;
    int dp[50];
    dp[0] = 1; dp[1] = 1;
    for(int i = 0; i <= n; i++){
        if(i >= 2)dp[i] = dp[i - 1] + dp[i - 2];
    }
    cout << dp[n] << endl;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdlib>
#include <string>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <random>
#include <map>

using namespace std;

int fibArray[50];

void makeFibArray() {
    for (int i = 2; i <= 46; i++) {
	fibArray[i] = fibArray[i - 1] + fibArray[i - 2];
    }
}

int main() {

    //cin.tie(0);
    //ios::sync_with_stdio(false);

    int n; scanf("%d", &n);
    fibArray[0] = 1;
    fibArray[1] = 1;
    makeFibArray();
    printf("%d", fibArray[n]);


    return 0;

}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const ll mod2 = 998244353;
const int INF = 1000000005;

int main() {
  int n;
  cin >> n;
  ll dp[n];
  dp[0] = 1;
  dp[1] = 1;
  FOR(i, 2, n+1) {
    dp[i] = dp[i-1] + dp[i-2];
  }
  cout << dp[n] << endl;

  
  return 0;
}

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

int main(void) {
    cin >> num;
    int array[num] = {};
    array[0] = 1;
    array[1] = 1;
    for (int i= 2; i <= num; i++) array[i] = array[i - 1] + array[i - 2];
    cout << array[num] << endl;
}