Go: package main

import (
	"fmt"
)

const MAX = 45

var dp [MAX]int

func fin(n int) int {
	if dp[n] != 0 {
		return dp[n]
	}

	switch n {
	case 0:
		dp[n] = 1
	case 1:
		dp[n] = 1
	default:
		dp[n] = fin(n-1) + fin(n-2)
	}
	return dp[n]
}

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

C++: #include <iostream>

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

    int r1 = 1;
    int r2 = 1;
    int result = 1;

    if (n == 1) {
        std::cout << 1 << std::endl;
    } else {
        for (int i = 1; i < n; i++) {
            int tmp = r1;
            r1 = r2;
            r2 = result;
            result += r1;
        }
        std::cout << result << std::endl;
    }
}

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

int main(){
  int f[45];

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

  int n; cin >> n;
  cout << f[n] << endl;
}

C++: #include <iostream>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string>
#include <vector>
#include <cctype>
#include <cstdio>
#include <iomanip>
#include <functional>
#include <stack>
#define PI 3.1415926535
#define INF 114514810
#define FOR(i, r, n) for(int i=(r); i<(n); i++) 
#define REP(i, n) FOR(i, (0), n)

using namespace std;

long long int n;

int fib(int k){
	if (k == 0 || k == 1) return 1;
	return fib(k - 1) + fib(k - 2);
}

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

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

using namespace std;

int main() {

	int n;
	cin >> n;

	int oold = 1;
	int old = 1;
	int neww;

	if (n == 0 || n == 1) { cout << 1 << endl; return 0; }

	for (int i = 2; i <= n; i++) {
		neww = old + oold;
		oold = old;
		old = neww;
	}

	cout << neww << endl;

	return 0;

}

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

int F[100];
int n;
int main() {
  F[0] = 1;
  F[1] = 1;
  cin >> n;
  for (int i=2; i<45; ++i) {
    F[i] = F[i-2]+F[i-1];
  }
  cout << F[n] << endl;
}

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

#define FOR(i, a, b) for(int i = (a); i < (b); i++)

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

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

int main() {
	int n;
	cin >> n;
	int dp[45];
	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 <stdio.h>
#include <cstring>
#include <math.h>
#include <algorithm>
#include <vector>
#include <string>
#include <stdlib.h>
#include <queue>
#include <stack>
#include <utility>
#define rep(i,n) for(int i=0;i<n;i++)
#define rrep(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define ll long long
#define INF 1000000001
#define mod 1000000007
using namespace std;

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

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

C++: #include <bits/stdc++.h>
using namespace std;
int main(){
  int n;
  cin >> n;
  vector<long long> fib(n + 1, 1);
  for (int i = 2; i <= n; i++){
    fib[i] = fib[i - 1] + fib[i - 2];
  }
  cout << fib[n] << endl;
}

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

const int N = 44;
int dp[N] = {};
int n;

int rec(int x)
{
	if(x == 0 || x == 1){
		dp[x] = 1;
		return dp[x];
	}
	
	if(dp[x] != 0)
		return dp[x];
	
	return dp[x] = rec(x - 1) + rec(x - 2);
}

int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	cin >> n;
	
	cout << rec(n) << endl;
	
	return 0;
}

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

const int MAX = 100;
long long dp[MAX];

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

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

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

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

C++: #ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif




#define int long long
#define rng(i,l,r) for(size_t i=(l);i<(r);++i)
#define rep(i,n) rng(i,0,n)
#define gnr(i,l,r) for(size_t i=(r)-1;i>=(l);i--)
#define per(i,b) gnr(i,0,b)
#define ALL(obj) (obj).begin(), (obj).end()   //1,2,3,...
#define rALL(obj) (obj).rbegin(), (obj).rend()//...,3,2,1

using namespace std;
//using ll = long long;


const int MOD = 1000000007;
const int INF = 1e18;

const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1,1,0,-1,-1,-1,0,1};
const int dy8[8] = {0,1,1,1,0,-1,-1,-1};

const double pi = acos(-1);



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


using Graph = vector<vector<int>>;
int gcd(int a,int b){return b?gcd(b,a%b):a;}
//*max_element(ALL(vector))
//count(ALL(vector),num) -> n




void solve(){
    
    // remove the bottom 3 lines when you submit this code.
    std::ifstream in("sample.txt");
    std::cin.rdbuf(in.rdbuf());

    cin.tie(0);
    ios::sync_with_stdio(false);
    
    int n; cin >> n;
    vector<int> fib(100);
    for (int i = 0; i < 100; i++) {
        
        if(i<=1) fib[i] = 1;
        else{
            fib[i] = fib[i-1] + fib[i-2];
        }
    }
    cout << fib[n] << endl;
}



signed main() {
    solve();
    return 0;
}

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

vector<int> fibonatti;
long long int  dp[10000];
int calc(int n){
  if(n <= 1) return 1;
  if(dp[n] != -1)return dp[n];
  fibonatti[n] = calc(n - 1) + calc(n - 2);
  return dp[n] = fibonatti[n];
}

int main(int argc, char *argv[]){
  int n;
  cin >> n;
  fibonatti.resize(n);
  fibonatti[0] = fibonatti[1] = 1;
  for (int i = 0; i <= n; i++) {
    dp[i] = -1;
  }
  dp[0] = dp[1] = 1;
  std::cout << calc(n) << std::endl;
  return 0;
}