Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func fibonacci_(n int) int {
	if n == 0 || n == 1 {
		return 1
	}
	return fibonacci_(n-2) + fibonacci_(n-1)
}

//メモ再帰の利用
func fibonacci(n int) int {
	if n == 0 || n == 1 {
		F[n] = 1
	}
	//F[n]が計算済みの場合
	if F[n] > 0 {
		return F[n]
	}
	F[n] = fibonacci(n-2) + fibonacci(n-1)
	return F[n]
}

const MAX = 50

var F [MAX]int

func main() {
	sc.Split(bufio.ScanWords)
	n := nextInt()
	fmt.Println(fibonacci(n))

}

C++: #include <iostream>

int F[50];
int main() {
    int n;
    scanf("%d", &n);

    for (int i = 0; i <= n; i++) {
        if (i <= 1) F[i] = 1;
        else {
            F[i] = F[i-1] + F[i-2];
        }
    }
    printf("%d\n", F[n]);
}

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

#define rep(i, a, n)  for(ll i=a; i<n; i++)
#define per(i, a, n)  for(ll i=n-1; i>=a; i--)
#define fill0(n)  setfill('0') << right << setw(n)
#define all(x)  (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define LONGMAX 1e18
#define INTMAX 1000000000

using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
const ll mod = 1e9+7;
const long double EPS = 0.0000000001;


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

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
//#include "MyMath.h"
//#include "MyDisjointset.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <functional>
#include <stdio.h>
#include <math.h>
#include <string.h>
using namespace std;
typedef pair<int, int> P; typedef long long int ll;
const int INF = 100000000;
int mod = 10000;
vector <vector<int> > mul(vector<vector<int> > f, vector<vector<int> > s) {
	vector<vector<int> > res(2, vector <int> (2) );
	res[0][0] = (f[0][0] * s[0][0] + f[0][1] * s[1][0]) % mod;
	res[0][1] = (f[0][0] * s[0][1] + f[0][1] * s[1][1]) % mod;
	res[1][0] = (f[1][0] * s[0][0] + f[1][1] * s[1][0]) % mod;
	res[1][1] = (f[1][0] * s[0][1] + f[1][1] * s[1][1]) % mod;
	return res;
}
int main() {
	int n; cin >> n;
	vector<vector<int> > base(2, vector<int> (2) );
	base[0][0] = 1;
	base[0][1] = 1;
	base[1][0] = 1;
	base[1][1] = 0;
	vector<vector<int> > ans(2, vector<int>(2));
	ans[0][0] = 1;
	ans[0][1] = 0;
	ans[1][0] = 0;
	ans[1][1] = 1;
	while (n > 0) {
		if (n & 1) ans = mul(ans, base);
		//cout << ans[0][0] << " " << ans[0][1] << endl;
		//cout << ans[1][0] << " " << ans[1][1] << endl;
		//cout << endl;
		base = mul(base, base);
		n >>= 1;
	}
	cout << ans[1][0] + ans[1][1]  << endl;
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define ms(s,x) memset(s,x,sizeof(s))
#define ls rt<<1
#define rs rt<<1|1
#define pb push_back
#define inf 0x3f3f3f3f
#define IOS ios::sync_with_stdio(false)
typedef long long ll;
using namespace std;

const double PI = acos(-1.0);
const double eps = 1e-8;
const int MAXN = 1e5+5;
const ll MOD = 1e9+7;
const int N = 1e5;

int main()
{
    ll fib[45] = {1, 1};
    int n;
    cin >> n;
    rep(i, 2, n){
        fib[i] = fib[i-1] + fib[i-2];
    }
    cout << fib[n] << endl;

    return 0;
}

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

using lli = long long int;
std::vector<lli> vec;
int main() {
    int n;
    std::cin >> n;
    vec.assign(n+1, 0);
    vec[0] = 1;
    vec[1] = 1;
    for (int i = 2; i <= n; i++) {
        vec[i] = vec[i-1] + vec[i-2];
    }
    std::cout << vec[n] << std::endl;

}

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

int main() {
	int n; cin >> n;
	vector<int> F(50, 0);

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

	cout << F[n] << endl;
}

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

int f[45];
int n;

int fibonacci(int n){
	
	cin >> n;
	f[0]=f[1]=1;

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


int main(){
	cout << fibonacci(n) << "\n";
    return 0;
}

C++: #include <iostream>
using ll = long long;
using namespace std;
#define MAX 50
/* initialize */
int fibs[MAX];

/* main */
int main() {

    int n;
    cin >> n;
    fibs[0]=fibs[1] = 1;
    for (int i = 2; i <= n; i++) {
        fibs[i] = fibs[i-1] + fibs[i-2];
    }
    cout << fibs[n] << "\n";
    return 0;
}

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

// // TLEとなってしまう実装
// int fib(int n)
// {
//   // ベースケース
//   if (n == 0)
//   {
//     return 1;
//   }
//   if (n == 1)
//   {
//     return 1;
//   }
//   // 再帰ステップ
//   return fib(n - 1) + fib(n - 2);
// }

vector<int> F(100, 0);

int fib(int n)
{
  // n項目を計算済みのとき
  if (F.at(n) > 0)
  {
    return F.at(n);
  }
  // n項目を未計算のとき
  if (n == 0 || n == 1)
  {
    F.at(n) = 1;
  }
  else
  {
    F.at(n) = fib(n - 1) + fib(n - 2);
  }
  return F.at(n);
}

int main()
{
  int n;
  cin >> n;
  cout << fib(n) << endl;
}

C++: #include <iostream>
#define SIZE 44
using namespace std;

int F[SIZE];

int Fibonacci(int n)
{
    if (n == 1 || n == 0)
    {
        return F[n] = 1;
    }
    if (F[n])
    {
        return F[n];
    }
    return F[n] = Fibonacci(n - 1) + Fibonacci(n - 2);
}

int main()
{
    int n;
    cin >> n;
    cout << Fibonacci(n) << endl;

    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;
}

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

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

	int ans = 1;
	if( n == 0 || n == 1 ) {
	}
	else {
		vector<int> dp( n + 1 );
		dp[0] = 1;
		dp[1] = 1;
		for( int i = 2; i < n + 1; i++ ) {
			dp[i] = dp[i - 1] + dp[i - 2];
		}
		ans = dp[n];
	}

	cout << ans << endl;
}

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

void fnInput(vector<int>& rvnFibDP)
{
  int nMaxSiz;
  cin >> nMaxSiz;
  rvnFibDP.resize(nMaxSiz + 1, 0);

  if (nMaxSiz >= 1)  
    rvnFibDP[0] = rvnFibDP[1] = 1;
  else
    rvnFibDP[0] = 1;
}

int fnFibNumber(vector<int>& rvnFibDP, int nNo)
{
  if (rvnFibDP[nNo])  return rvnFibDP[nNo];

  return rvnFibDP[nNo] = 
         fnFibNumber(rvnFibDP, nNo - 1) + fnFibNumber(rvnFibDP, nNo - 2);
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<int> vnFibDP; 

  fnInput(vnFibDP);
  cout << fnFibNumber(vnFibDP, vnFibDP.size() - 1) << endl;
  return 0;
}

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

using namespace std;


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

    vector<int> dp(n+1, 0);

    dp[0] = 1, dp[1] = 1;

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

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

C++: #include <iostream>
#include <string>
#include <cstring>
#include <fstream>
#include <cmath>
#include <iomanip>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <deque>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <unordered_map>



using namespace std;

int main() {
   

    long long n;
    cin >> n;
    long long F[50];
    F[0] = F[1] = 1;
    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;

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-1] << endl;
  return 0;
}