Go: package main

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

// func fib(n int) int{
// 	if n == 0 || n == 1{
// 		return 1
// 	} else {
// 		return fib(n-1) + fib(n-2)
// 	}
// }

// func main(){
// 	sc := bufio.NewScanner(os.Stdin)
// 	sc.Scan()
// 	n, _ := strconv.Atoi(sc.Text())
// 	fmt.Println(fib(n))
// }

import (
	"fmt"
)

func main(){
	var n, pre1, pre2, now int
	fmt.Scan(&n)
	if n == 0 || n == 1{
		fmt.Println(1)
	} else {
		pre1, pre2 = 1, 1
		for i:=1; i<n; i++{
			now = pre1 + pre2
			pre2 = pre1
			pre1 = now
		}
		fmt.Println(now)
	}

}

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

#define MAX 44

int F[MAX];

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] << endl;

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0; i<(n); i++)
#define REP2(i,x,n) for(int i=x; i<(n); i++)
#define PRINT(x) cout<<(x)<<endl
#define INF 1000000000000 // 10^12
#define MOD 1000000007 // 10^9+7
#define PB push_back
#define MP make_pair

const int MAX_N = 44;

int n;

int dp[MAX_N];

int main() {
    cin >> n;
    dp[0] = 1, dp[1] = 1;
    REP2(i, 2, n+1) dp[i] = dp[i-1] + dp[i-2];
    PRINT(dp[n]);
    return 0;
}

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

const int Max = 50;
int F[Max];

int Fib(int n)
{
    F[0] = 1;
    F[1] = 1;
    if(n==0 || n==1) return F[n];
    if(!F[n-1])
        F[n-1] = Fib(n-1);
    if(!F[n-2])
        F[n-2] = Fib(n-2);
    return F[n-1]+F[n-2];
}
int main()
{
    int n;
    cin >> n;
    memset(F, 0, sizeof(F));
    cout << Fib(n) << endl;
}

C++: #include <iostream>

using namespace std;
int fib(int n){
    int dp[50];
    dp[0] = 1;
    dp[1] = 1;
    for(int i = 2; i < 45; ++i){
        dp[i] = dp[i-1] + dp[i-2];
    }
    return dp[n];
}

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

C++: #include <iostream>
#include <fstream>
#include <stdio.h>
#include <algorithm>

#define MAX 1000000

using namespace std;

int fib[MAX];

int solve(int a){
    if(fib[a])return fib[a];
    if(!fib[a-2])fib[a-2] = solve(a-2);
    if(!fib[a-1])fib[a-1] = solve(a-1);
    return fib[a-1]+fib[a-2];
}

int main(int argc, const char * argv[]) {
    // input from txt
    
    /////////
    //write//
    /////////
    
    fill(fib, fib+MAX, 0);
    fib[0] = 1;
    fib[1] = 1;
    int num; cin >> num;
    cout << solve(num) << endl;
    
    return 0;
}

C++: #include <cstdio>

using namespace std;

int main()
{
    int n;
    scanf("%d", &n);
    int sum;
    if(n==0){
        sum=1;
    } else if(n==1){
        sum=1;
    } else{
        int older=1, oldest=1;
        sum=0;
        for(int i=2; i<=n; i++){
            sum=older+oldest;
            oldest=older;
            older=sum;
        }
    }
    printf("%d\n", sum);
    return 0;
}

C++: #include <stdlib.h>
#include <stdio.h>

int fib(int n){
int i;
int a[25];
a[0]=a[1]=1;
for(i=2;i<n;i++){
a[i]=a[i-1]+a[i-2];
   }
return a[i];
}

int main(){

int x;
scanf("%d",&n);
x=fib(n);
printf("%d",x);

return 0;
}

C++: #include <iostream>
using namespace std;
int fib(int n) {
    if(n==1) 
        return 1;
    else if(n==2)
        return 2;
    else
        return fib(n-1) + fib(n-2);
}
int main(void){
    int n;
    cin >> n ;
    cout << fib(n) << endl;
    return 0;
}

C++: #include <iostream>

using namespace std;

int fib(int n);

int main() {
    int n;
    int dp[45];

    //?????????
    /* ??????3-1 */
    dp[0] = dp[1] = 1;
    /* ??????3-2 */

    //??\???
    cin >> n;

    //DP
    for (int i = 2; i <= n; i++) {
        /* ??????3-3 */
      dp[i] = dp[i-1] + dp[i-2];
    }

    //??????
    cout << dp[n] << endl;

    return 0;
}

C++: #include<iostream>
using namespace std;
int nrec(int n){
    int a[44];
    a[0]=a[1]=1;
    for(int i=2;i<=n;i++){
        a[i]=a[i-1]+a[i-2];  
    }
    return a[n];
}

int main(){
    int n;
    cin>>n;
    cout<<nrec(n)<<endl;
    return 0;
}

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

uint32_t fib(uint32_t n, std::vector<uint32_t>& result) {
  if (n == 0 || n == 1) return 1;
  if (result[n - 1] != 0) return result[n - 1];
  result[n - 1] = fib(n - 1, result) + fib(n - 2, result);
  return result[n - 1];
}

int main() {
  uint32_t n = 0;
  std::cin >> n;

  std::vector<uint32_t> result(n, 0);
  std::cout << fib(n, result) << std::endl;
  return 0;
}

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

typedef long long ll;
typedef pair<int,int> P;

int main(){
	int n;
	cin>>n;
	int dp[50];
	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<bits/stdc++.h>

using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

#define MAX 100005
#define INF INT_MAX

typedef long long ll;
typedef pair<int, int> P;

int main(int, char**)
{
    int n;
    cin >> n;

    vector<int> a(n+1);
    rep(i,n+1) {
        if (i <= 1) {
            a[i] = 1;
            continue;
        }
        a[i] = a[i-1] + a[i-2];
    }
    cout << a[n] << endl;
    return 0;
}

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 <stdio.h>

#define N 44

int F[N];
int n;

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

	if(F[n] != 0) return F[n];

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

int main(){
	scanf("%d",&n);
	int i;
	for(i=0;i<n;i++){
		F[i] = 0;
	}
	fib(n);
	printf("%d\n",F[n]);
}

C++: #include <iostream>

using namespace std;

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

	cout << n << "\t" << f[n] << endl;
}

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

int A[51];

void func(int n){
  if(n==50) return;
  A[n]=A[n-1]+A[n-2];
  func(n+1);
}

int main(){
  int n;
  cin >> n;
  A[0]=1; A[1]=1;
  func(2);

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

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

int main()
{
	int n;
	cin >> n;
	int dp[50];
	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 "bits/stdc++.h"
#include <unordered_set>

#define REP(i, n) for(decltype(n) i = 0; i < (n); i++)
#define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++)
#define REP3(i, x, n) for(decltype(x) i = (x); i <= (n); i++)
#define RREP(i, n) for (decltype(n) i = (n) - 1;i >= 0; i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

#define LL long long int
#define LD long double

#define INF 1000000000
#define PI 3.14159265358979323846

#define _CRT_SECURE_NO_WARNINGS

using namespace std;

// N, E, S, W
const int dx[4] = { -1, 0,  1,  0 };
const int dy[4] = { 0, 1,  0, -1 };

typedef pair<int, int> pii;
typedef pair<LL, LL> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<LL> vll;
//==============================================

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	int n; cin >> n;
	vi dp{1, 1};

	REP3(i, 2, n) {
		dp.push_back(dp[i - 1] + dp[i - 2]);
	}

	cout << dp[n] << "\n";
	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;
}

C++: #include <iostream>

using namespace std;

int ans[45] = {};

int fib(int n) {
	if (n <= 1) return 1;
	int a = ans[n];
	if (a) return a;
	a = fib(n-1) + fib(n-2);
	ans[n] = a;
	return a;
}

int main()
{
	int i = 0;
	cin >> i;
	cout << fib(i) << endl;
}