Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}
	fmt.Println(fibonacci(n, make(map[int]int)))
}

func fibonacci(x int, memo map[int]int) int {
	if x == 0 || x == 1 {
		return 1
	}
	if y, ok := memo[x]; ok {
		return y
	}
	z := fibonacci(x-1, memo) + fibonacci(x-2, memo)
	memo[x] = z
	return z
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

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

	return 0;
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
typedef long long int ll;
ll Dp[50];
int main()
{
for(int i=2;i<50;i++)Dp[i]=Dp[i-1]+Dp[i-2];
int N;
cin >> N;
cout << Dp[N] << "\n";

return 0;
}

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

int main(){
	int n;
	cin >> n;
	int fib[50];
	fib[0] = 1;
	fib[1] = 1;
	
	rep(i,n-1){
		fib[i+2] = fib[i+1] + fib[i];
	}
	
	cout << fib[n] << endl;
	
    return 0;
}

C++: #include <bits/stdc++.h>
#define pb push_back
using namespace std;
typedef long long ll;

int n,a[55];

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

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
//using ll = long long;
//using P = pair<int, int>;
 
int fib[50];

int main() {
    int n;
    cin >> n;
    
    fib[0] = 1;
    fib[1] = 1;
    
    if(n <= 1){
        cout << 1 << endl;
        return 0;
    }
    
    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 <vector>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;

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

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, m, n) for (int i = m; i < n; ++i)

int main() {
  int N; cin >> N;
  int dp[45];
  dp[0] = dp[1] = 1;
  rep(i, 1, N) dp[i + 1] = dp[i] + dp[i - 1];
  cout << dp[N] << endl;
  return 0;
}

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

//短縮
#define rep(i,n) for(int i=0;i<(n);++i)
//sort()用
#define all(v) v.begin(), v.end()

using namespace std;

using Graph = vector<vector<int>>;

int main(){
  int n;
  cin >> n;
  int n1=1,n2=1;
  vector<int> fib(n+1);
  fib.at(0)=1;
  fib.at(1)=1;
  for(int i=2;i<=n;i++){
    fib.at(i)=fib.at(i-1)+fib.at(i-2);
  }
  cout << fib.at(n)<< endl;
  return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <utility>
#include <algorithm>
#include <math.h>
#include <vector>
using namespace std;

int f[45] = {};

int fib(int i)
{
    if (f[i] > 0)
        return f[i];

    if (i == 0 || i == 1)
    {
        f[i] = 1;
    }
    else
    {
        f[i] = fib(i-1) + fib(i-2);
    }
    return f[i];
}

int main()
{
    int n;
    cin >> n;
    cout << fib(n) << "\n";
    return 0;
}

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

int main(){
    int f[45],n;
    cin>>n;
    f[0]=1;f[1]=1;
    for(int i=2;i<45;i++){
        f[i]=f[i-1]+f[i-2];
    }
    cout<<f[n-1]<<endl;
    return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_A
// Dynamic Programming - Fibonacci Number

#define SUBMIT

#include <utility>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <vector>
#include <limits>
#include <numeric>
#include <functional>
#include <set>
#include <cmath>
#include <cstring>
#include <climits>
#include <memory>

using namespace std;
using ui64 = unsigned long long;
using i64 = long long;

const ui64 MAX_N = 44;
int dp[MAX_N + 1];

int main() {
    // initialize
    memset(dp, 0, sizeof(dp));
    dp[0] = 1, dp[1] = 1;

    for (int i = 2; i <= MAX_N; ++i) dp[i] = dp[i - 1] + dp[i - 2];

    int n;
    cin >> n;

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

C++: #include<iostream>

using namespace std;
int fib(int n);

int memo[45];
int main(){
  int n;
  cin >> n;
  cout << fib(n) << endl;
  retrun 0;
}

int bib(int n){

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

  }

C++: #include <iostream>
#include <unordered_map>
using namespace std;
int fib(int);
unordered_map<int, int> memoFib;

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

int fib(int n) {
  if(memoFib.count(n)) return memoFib[n];
  int a;
  a = memoFib[n] = n == 0 || n == 1 ? 1 : fib(n - 1) + fib(n - 2);
  return a;
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<algorithm>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<deque>
#include<queue>
#include<map>
#include<set>
#define ll long long
#define vll vector<ll>
#define dou(s) atof(s.c_str())
#define lon(s) atoll(s.c_str())
#define str(n) to_string(n)
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define rrep(i,b,a) for(ll i=b;i>=a;i--)
#define ALL(a) a.begin(),a.end()
#define rALL(a) a.rbegin(),a.rend()
#define line "\n"
#define mav(a) (*max_element(ALL(a)))
#define miv(a) (*min_element(ALL(a)))
#define vfind(a,n) (find(ALL(a),n)-a.begin())
#define prque priority_queue
#define MOD 1000000007ll
using namespace std;
void solve();
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	solve();
}

//nCk(mod p)
/*ll fac[510000], finv[510000], inv[510000];
void cmodf(ll p = MOD) {
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	rep(i, 2, 510000) {
		fac[i] = fac[i - 1] * i%p;
		inv[i] = p - inv[p%i] * (p / i) % p;
		finv[i] = finv[i - 1] * inv[i] % p;
	}
}
ll cmod(ll n, ll k, ll p = MOD) {
	return fac[n] * (finv[k] * finv[n - k] % p) % p;
}*/

//最大公約数
ll gcd(ll n, ll m) {
	ll k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return m;
}
ll gcd(vector<ll> a) {
	rep(i, 1, a.size()) {
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
	}
	return a.back();
}

//最小公倍数
ll lcm(ll n, ll m) {
	ll t = n * m, k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return t / m;
}
ll lcm(vector<ll> a) {
	ll n;
	rep(i, 1, a.size()) {
		n = a[i - 1] * a[i];
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
		n /= a[i];
		a[i] = n;
	}
	return n;
}

//keyの小さい方から探していった時に初めてvalueがjoken以上になる時のkey（keyが増えたらvalueも増えるか同じになるとき）
ll value(ll key) {
	/*変更*/
	return 0;
}
ll mini(ll lkey, ll rkey/*ここも調べる*/, ll joken) {
	ll mkey;
	while (lkey != rkey) {
		mkey = (lkey + rkey) / 2;
		if (value(mkey) >= joken)rkey = mkey;
		else lkey = mkey + 1;
	}
	return rkey;
}

//ペア配列の整理
struct pea { ll n, m; };
void msort(vector<pea> &a, bool k = true) {
	struct hikakukansu {
		static bool unstable(const pea &x, const pea &y) { return x.m < y.m; }
		static bool stable(const pea &x, const pea &y) { return (x.m == y.m ? x.n < y.n : x.m < y.m); }
	};
	if (k)sort(ALL(a), hikakukansu::unstable);
	else sort(ALL(a), hikakukansu::stable);
}

//変数定義

//再帰関数

//アルゴリズム
void solve() {
	ll n; cin >> n;
	vll a(n+1,1);
	rep(i, 2, n+1)a[i] = a[i - 1] + a[i - 2];
	cout << a[n] << line;
}

C++: #include <iostream>

using namespace std;
int F[100];
int main() {
	int n;
	cin >> n;
	F[0] = 1;
	F[1] = 1;
	for (int i=2; i<=n; ++i) {
		F[i] = F[i-2] + F[i-1];
	}
	cout << F[n] << endl;
}