Go: package main

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

func main() {
        fp := os.Stdin
        scanner := bufio.NewScanner(fp)
        var lst [3]int

        for scanner.Scan() {
                num, _ := strconv.Atoi(scanner.Text())
                if lst[0] < num {
                        lst[2] = lst[1]
                        lst[1] = lst[0]
                        lst[0] = num
                } else if lst[1] < num {
                        lst[2] = lst[1]
                        lst[1] = num
                } else if lst[2] < num {
                        lst[2] = num
                }
        }

        for _, i := range lst {
                fmt.Printf("%d\n", i)
        }
}

C++: 
/*************************************************************************************
                         ---------------------------
                   ------Bismillahir-Rahmanir-Rahim------
                         ---------------------------

                    U         U            M           M
                    U         U            M  M     M  M
                    U         U            M     M     M
                    U         U            M           M
                    U         U            M           M
                    U         U   *        M           M     *
                    U         U  * *       M           M    * *
                      U  U  U     *        M           M     *
    -----------------------------------------------------------------------
            //     //   Name: MD: MEHEDI HASAN              //     //
           //     //    Institute: HSTU                    //     //
          //     //     Dept.: CSE                        //     //
         //     //      Email: mehedi1502032@gmail.com   //     //
    -----------------------------------------------------------------------
            ---------- I Love Programming as Gaming ----------
**************************************************************************************/
#include<algorithm>
#include<iostream>
#include <sstream>
#include<iomanip>
#include<cassert>
#include<cstdlib>
#include<cstring>
#include<utility>
#include<sstream>
#include<cctype>
#include<cstdio>
#include<string>
#include<vector>
#include<limits>
#include<queue>
#include<cmath>
#include<stack>
#include<ctime>
#include<list>
#include<map>
#include<set>

using namespace std;

#define loop(a,b,c) for(int a=b;a<c;a++)
#define lloop(a,b,c) for(long long a=b;a<c;a++)
#define rloop(a,b,c) for(int a=c-1;a>=b;a--)
#define rlloop(a,b,c) for(long long a=c-1;a>=b;a--)
#define EPS 1e-9
#define PI acos(-1)
#define rn PI/180
#define TC(t) scanf("%d",&t);while(t--)
#define sf scanf
#define pf printf
#define SIZE 100001
#define sp ' '
#define nl printf("\n")
#define pb push_back
#define pp pop_back
#define mp make_pair
#define ff first
#define ss second
#define gcd(a,b) __gcd(a,b)
#define b_s(v,x) binary_search(v.begin(),v.end(),x)
#define l_b(v,x) lower_bound(v.begin(),v.end(),x)
#define u_b(v,x) upper_bound(v.begin(),v.end(),x)
#define e_r(v,x) equal_range(v.begin(),v.end(),x)

/// ASCII Vlaue....
/// A=65,Z=90,a=97,z=122,0=48,9=57


const int MOD=1000000007;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> vi;
typedef vector<string> vs;
typedef stack<int> si;
typedef stack<string> ss;
typedef queue<int> qi;
typedef queue<string> qs;
typedef pair<int,int> pii;
typedef pair<string,int>psi;

ll nCr(ll aan, ll aar)
{
    ll ii, aac=1;
    for(ii=1; ii<=aar; ii++)
    {
        aac*=(aan-aar+ii);
        aac/=ii;
    }
    return aac;
}

bool status[1100002];
void siv()
{
	int N=1000000;
	int sq=sqrt(N);
	for(int i=4;i<=N;i+=2) status[i]=1;
	for(int i=3;i<=sq;i+=2){
		if(status[i]==0)
		{
			for(int j=i*i;j<=N;j+=i) status[j]=1;
		}
	}
	status[1]=1;
}

ll big_mod(ll base, ll power, ll mod)
{
    if(power==0) return 1;
    if(power&1)
    {
        ll p1=base%mod;
        ll p2=(big_mod(base, power-1,mod))%mod;
        return (p1*p2)%mod;
    }
    else
    {
        ll p1=(big_mod(base,power/2,mod))%mod;
        return (p1*p1)%mod;
    }
}
ll modInverseBigMod(ll a,ll m)  //a*x=1(mod m)
{
    return big_mod(a,m-2,m);
}

///START YOUR CODE FROM HERE.... Happy Coding.... ! ;)

int main()
{
    int a[11];
    loop(i,0,10) cin>>a[i];
    sort(a,a+10);
    cout<<a[9]<<endl<<a[8]<<endl<<a[7]<<endl;




    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
int main(){
	int h;
	std::vector<int> heights;
	for(int i=0; i<10; i++){
		std::cin >> h;
		heights.push_back(h);
	}
	std::sort(heights.begin(), heights.end(), std::greater<int>());
	int i=0;
	for(std::vector<int>::iterator it=heights.begin();
		i<3 && it!=heights.end(); i++, it++){
			std::cout << *it << '\n';
	}
}

C++: #include<iostream>
 using namespace std;
int main(){
int input[10];
int first;
int second;
int third;
for(int i=0;i<10;i++){
cin>>input[i];
}
for(int i=0;i<30;i++){
if(first<input[i]){first = input[i];}
else if(second<input[i-10]){second = input[i-10];}
else if(third<input[i-20]){third = input[i-20];}
}
cout<<first<<endl;
cout<<second<<endl;
cout<<third<<endl;
return 0;

}

C++: #include<iostream>
 using namespace std;
int main(){
	int input[10];
	int first;
	int second;
	int third;
	for(int i;i<10;i++){
		cin>>input[i];
	}
	for(int i;i<10;i++){
	if(input[i]>first){
	first = input[i];
        input[i] = 0;
	}
	}
	for(int i;i<10;i++){
	if(input[i]>second){
	second = input[i];
        input[i] = 0;
	}
	}
	for(int i;i<10;i++){
	if(input[i]>first){
	third = input[i];
	}
	}
	cout<<first<<endl;cout<<second<<endl;cout<<third<<endl;
	return 0;

}

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

vector<int> v;
int t;

int main(){
	REP(i, 10) {
		cin >> t;
		v.push_back(t);
	}
	sort(v.begin(), v.end());
	cout << v[9] << endl << v[8] << endl << v[7] << endl;
}

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

int main(void){
    int i;
    vector<int> v;
    while(getline(cin, num)){
        v.push_back(num);
    }
    sort(v.begin(), v.end());
    for(int i = 1; i < 4; i++){
        cout << v[v.size - i] << endl;
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
int main()
{
    int i,j,a[11];
    int m1=0,m2=0,m3=0;
    for(i=0;i<10;i++)
    {
        cin>>a[i];
    }
   sort(a,a+10);

   cout<<a[9]<<endl<<a[8]<<endl<<a[7]<<endl;
    return 0;
}

C++: /*
C++ ???????????????????????????????????¬??????
??????AOJ-ITP1??????????????????
*/
#define _USE_MATH_DEFINES

#include <iostream> // ?¨??????\??????
#include <fstream>  // ??????????????\??????
#include <string>   // ???????????¢???
#include <vector>   // ???????????????
#include <cmath>    // ??°??????
#include <iomanip>  // stream???????????¢???
#include <algorithm>// max??¢??°??????

using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;        // ????´???°????????????????????????
using std::fixed;         // ???????????????????¨???????????????????????????????
using std::setprecision;  // ?????°????°???°?????\???????????°????????????????????¨????????\???

int main() {
	vector<int> height;	// ??\???????????????????´?????????????
	int h;				// ??\?????????????????????????´??????°

	// 10????????\?????????????????????
	for (size_t i = 0; i < 10; i++)
	{
		cin >> h;
		height.push_back(h);
	}
	// ????????????
	std::sort(height.begin(), height.end());

	// ??????
	cout << height[9] << endl;
	cout << height[8] << endl;
	cout << height[7] << endl;
	return 0;
}

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

int main() {
  std::vector<int> heights;
  for (auto i =0; i < 10; i++) {
    int h;
    std::cin >> h;
    heights.push_back(h);
  }
  std::sort(heights.begin(), heights.end(), std::greater<int>());
  for (auto i =0; i < 3; i++) {
    std::cout << heights[i] << '\n';
  }
  return 0;
}