Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()
	n := nint()
	r := fibonacci(n)
	fmt.Println(r)
}

func fibonacci(n int) int{
	if n == 0 || n == 1{
		return 1
	}else{
		fiList := make([]int, n+1)
		fiList[0] = 1
		fiList[1] = 1
		for i:=2; i<n+1; i++{
			fiList[i] = fiList[i-1] + fiList[i-2]
		}
		return fiList[n]

	}

}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

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

#define _sel(_1, _2, x, ...) x
#define repn(i, n) for (ll i = 0; i < (n); i++)
#define reps(i, a, b) for (ll i = (a); i < (b); i++)
#define rep(i, ...) _sel(__VA_ARGS__, reps, repn)(i, __VA_ARGS__)
#define reppn(i, n) for (ll i = 1; i <= (n); i++)
#define repps(i, a, b) for (ll i = (a); i <= (b); i++)
#define repp(i, ...) _sel(__VA_ARGS__, repps, reppn)(i, __VA_ARGS__)
#define rrepn(i, n) for (ll i = (n) - 1; i >= 0; i--)
#define rreps(i, a, b) for (ll i = (b) - 1; i >= (a); i--)
#define rrep(i, ...) _sel(__VA_ARGS__, rreps, rrepn)(i, __VA_ARGS__)
#define rreppn(i, n) for (ll i = (n); i >= 1; i--)
#define rrepps(i, a, b) for (ll i = (b); i >= (a); i--)
#define rrepp(i, ...) _sel(__VA_ARGS__, rrepps, rreppn)(i, __VA_ARGS__)

#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define rng(v) (v).begin(), (v).end()
#define rrng(v) (v).rbegin(), (v).rend()
#define _shv(v) for (auto _t1 : v) cerr << _t1 << " "; cerr << endl;
#define dbg(x) cerr << #x << ": " << (x) << endl;
#define dbgv(v) cerr << #v << ": "; _shv(v);
#define dbgm(m) cerr << #m << ":" << endl; for (auto _t2 : m) { _shv(_t2); }

using namespace std;
using ll = long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
using vc = vector<char>;
using vs = vector<string>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vvb = vector<vector<bool>>;
using vvc = vector<vector<char>>;
using vvs = vector<vector<string>>;

const int INF = 1e9;
const ll LINF = 1e18;
const ll MOD = 1e9 + 7;
const int DX[4] = {1, 0, -1, 0};
const int DY[4] = {0, 1, 0, -1};

inline void yn(bool f) { cout << (f ? "Yes" : "No") << endl; }
template<typename T> inline void prt(T x) { cout << (x) << endl; }
template<typename T> inline void prtv(T& v) { for (auto t : v) cout << t << " "; cout << endl; }
template<typename T> inline void prtl(T& v) { for (auto t : v) cout << t << endl; }
template<typename T> inline T pop(stack<T>& x) { T t = x.top(); x.pop(); return t; }
template<typename T> inline T pop(queue<T>& x) { T t = x.front(); x.pop(); return t; }
template<typename T> inline T pop(priority_queue<T>& x) { T t = x.top(); x.pop(); return t; }
template<typename T> inline int sz(T& x) { return x.size(); }
template<typename T> inline ll pow2(T n) { return 1ll << n; }
template<typename T, typename U> inline int bit(T x, U n) { return x >> n & 1; }

template<typename T, typename U>
inline void getv(T& v, U n) { v = T(n); rep(i, n) cin >> v[i]; }
template<typename T, typename U>
inline void inv(T& v, U n) { v = T(n); rep(i, n) { cin >> v[i]; v[i]--; } }
template<typename T, typename U>
inline void getm(T& v, U r, U c) { v = T(r); rep(i, r) getv(v[i], c); }
template<typename T, typename U>
inline void inm(T& v, U r, U c) { v = T(r); rep(i, r) inv(v[i], c); }
template<typename T, typename U>
inline bool cmax(T& m, U x) { if (m < x) { m = x; return true; } return false; }
template<typename T, typename U>
inline bool cmin(T& m, U x) { if (m > x) { m = x; return true; } return false; }


int main() {
    int n;
    cin >> n;
    if (n <= 1) {
        prt(1);
        return 0;
    }
    vl f(n + 1, 1);
    repp(i, 2, n) {
        f[i] = f[i - 1] + f[i - 2];
    }
    prt(f[n]);

    return 0;
}

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

vector<int> dp;

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

int main(){
    int n; cin >> n;
    dp.assign(n+1,-1);
    dp[0]=1;
    dp[1]=1;
    cout << fib(n) << endl;
}
//g++ -o proa.exe proa.cpp

//VSCなら./test
//Atomならtest.exe

C++: #include <bits/stdc++.h>
#define lp(n) for(int i = 0; i < n; i++)
using namespace std;
int main(){
  int n;
  unsigned long long A[45];
  A[0] = 1;
  A[1] = 1;
  for(int i = 2; i <= 44; i++) A[i] = A[i-1] + A[i-2];
  cin >> n;
  cout << A[n] << endl;
  return 0;
}

C++: #include <cstdio>

int compute_fibonacci(int num)
{
    int prev_num = 1;
    int current_num = 1;
    for(int i = 2; i <= num; i++) {
        int tmp = current_num;
        current_num = current_num + prev_num;
        prev_num = tmp;
    }
    return current_num;
}

int main()
{
    int num;
    scanf("%d", &num);
    printf("%d\n", compute_fibonacci(num));
    return 0;
}

C++: #define PI 3.14159265359
#define INF 2000000000
#define MAX 500000
#include <map>
#include <algorithm>
#include <vector>
#include <queue>
#include <iostream>
#include <string>
#include <cstring>
#include <cmath>
#include <cstdio>
using namespace std;
typedef long long ll;

int main(){
    ll F[45]={0};
    int n;
    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;
}