Go: package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)

	x, y := int64(0), int64(1)
	for i := 0; i < n; i++ {
		x, y = y, x+y
	}

	fmt.Println(x)
}

C++: #include <bits/stdc++.h>
using namespace std;
int a[45];
int fib(int n)
{
    if(a[n]>0)
        return a[n];
    return a[n]=fib(n-2)+fib(n-1);
}
int main()
{
    a[1]=a[0]=1;
    int n;
    cin>>n;
    cout<<fib(n)<<endl;
    return 0;
}

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

int main(){

    int fib[50];
    fib[0] = fib[1] = 1;
    for(int i = 2; i <= 45; i++){
        fib[i] = fib[i - 1] + fib[i - 2];
    }

    int n; cin >> n;
    cout << fib[n] << endl;
    return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<cstdio>
#include<sstream>
#include<algorithm>
#include<cmath>
#include<map>
using namespace std;
int dp[50];
int main(){
	int n;
	cin>>n;
	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>

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define debug(x) cerr << x << " " \
                      << "(L:" << __LINE__ << ")" << '\n'

//DP法
template <class T>
inline bool chmin(T &a, T b) //change minimum
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T &a, T b) //change max
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}

typedef long long ll; //64bit型
using namespace std;

const long long INF = 1LL << 60; //無限大の値
int N;
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 <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1LL << 60;
const int MAX = 1000000010;
const ll MOD = 1000000007;
const double PI = acos(-1);

int main() {
    int N; cin >> N;
    vector<int> fib(N + 1);
    fib[0] = 1; 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<bits/stdc++.h>
using namespace std;

int f[50];

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

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

  cout << fibo(n) << endl;
  return 0;
}

C++: #include <cstdio>
using namespace std;
unsigned long long fib[45];
int main() {
    fib[0] = 1;
    fib[1] = 1;
    int n;
    scanf("%d", &n);
    for (int i = 2; i <= n; i++) {
    	fib[i] = fib[i - 1] + fib[i - 2];
	}
	printf("%lld\n", fib[n]);
    return 0;
}

C++: #include <iostream>
using namespace std;
int F[100];
int Fibonacci(int N) {
  F[0] = 1;
  F[1] = 1;

  for (int i = 2; i <= N; ++i) {
    F[i] = F[i-2] + F[i-1];
  }
  return F[N];
}
int main() {


  int N;
  cin >> N;
  cout << Fibonacci(N)<<endl;
}

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

#define rep(i,n) for(int (i)=0;(i)<(n);++(i))
#define FOR(i,a,b) for(int (i)=(a);i<(n);++(i))
#define ALL(obj) (obj).begin(),(obj).end()
#define space <<" "<<
using namespace std;

    vector<long> dp;

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

int main(){

    int n;
    cin>>n;

    dp.assign(n+1,-1);
    cout <<fib(n)<< endl;
   
}

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

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

#define pb push_back
#define rep(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, n) for(int i = a; i < (n); i++)
#define mod (ll)(1e9+7)
#define int ll

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

signed main() {
	ll n, f[50] = {0};
  cin >> n;
  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 <stdio.h>

int fib(int);

int main()
{
  int n,total=0;

  scanf("%d",&n);

  total=fib(n);

  printf("%d\n",total);

 
  return 0;
}    


int fib(int n){

  static int total=0;

  if(n==0) return ++total;
  else if (n==1) total++;
  else fib(n-1)+fib(n-2);
}

C++: #include <algorithm>
#include <climits>
#include <iostream>
#include <string>
#include<cstdio>
#include <vector>
#include<queue>
#include<limits.h>
#include<string.h>
#include<functional>
#include<map>
#include<set>
#include<list>
#include<unordered_map>
#include<queue>
#define int long long
using namespace std;

signed main(){
	int a; cin >> a;
	int b = 0, c = 1;
	for (int d = 0; d < a; d++) {
		int e = b + c;
		b = c;
		c = e;
	}
	cout << c << endl;
}

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>
using namespace std;
int main(){
  int n;
  long long int fib1,fib2,fib3;
  cin>>n;
  fib1=1;
  fib2=1;
  for(int i=0;i<n-1;i++){
    fib3=fib1+fib2;
    fib1=fib2;
    fib2=fib3;
  }
  cout<<fib3<<endl;
}

C++: // Algorithms and Data Structures 1
// Fibonacci Numbers
// Name: Ryuya Asada
// ID: s1260064

#include <iostream>

int fibonacci(int);

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

    std::cout << fibonacci(n) << "\n";

    return 0;
}

int fibonacci(int n) {
    int a(0), b(1), c(1);
    for(int i=1; i <= n; ++i) {
        c = a + b;
        a = b;
        b = c;
    }

    return c;
}

C++: #include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i,n) for (int i=0;i<(int)(n);i++)
#define codefor int test;scanf("%d",&test);while(test--)
#define yn(ans) if(ans)printf("Yes\n");else printf("No\n")
#define YN(ans) if(ans)printf("YES\n");else printf("NO\n")
#define vector2d(type,name,h,...) vector<vector<type>>name(h,vector<type>(__VA_ARGS__))
#define umap unordered_map
#define uset unordered_set
using namespace std;
using ll = long long;
const int MOD=1000000007;
//入力系
void scan(int& a){scanf("%d",&a);}
void scan(long long& a){scanf("%lld",&a);}
template<class T> void scan(T& a){cin>>a;}
template<class T> void scan(vector<T>& vec){for(auto&& it:vec)scan(it);}
void in(){}
template <class Head, class... Tail> void in(Head& head, Tail&... tail){scan(head);in(tail...);}
//出力系
void print(const int& a){printf("%d",a);}
void print(const long long& a){printf("%lld",a);}
void print(const double& a){printf("%.15lf",a);}
template<class T> void print(const T& a){cout<<a;}
template<class T> void print(const vector<T>& vec){if(vec.empty())return;print(vec[0]);for(auto it=vec.begin();++it!= vec.end();){putchar(' ');print(*it);}}
void out(){putchar('\n');}
template<class T> void out(const T& t){print(t);putchar('\n');}
template <class Head, class... Tail> void out(const Head& head,const Tail&... tail){print(head);putchar(' ');out(tail...);}
//デバッグ系
template<class T> void dprint(const T& a){cerr<<a;}
template<class T> void dprint(const vector<T>& vec){if(vec.empty())return;cerr<<vec[0];for(auto it=vec.begin();++it!= vec.end();){cerr<<" "<<*it;}}
void debug(){cerr<<endl;}
template<class T> void debug(const T& t){dprint(t);cerr<<endl;}
template <class Head, class... Tail> void debug(const Head& head, const Tail&... tail){dprint(head);cerr<<" ";debug(tail...);}

vector<ll> fibo(50,-1);
ll fibonacci(ll n){
    if(fibo[n]!=-1){
        return fibo[n];
    }else if(n==0){
        fibo[0]=1;
        return 1;
    }else if(n==1){
        fibo[1]=1;
        return 1;
    }else{
        fibo[n]=fibonacci(n-2)+fibonacci(n-1);
        return fibo[n];
    }
}

int main(){
    int n;
    in(n);
    out(fibonacci(n));
}