Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

type Pair struct {
	key   string
	value int
}

func main() {
	scanner.Split(bufio.ScanWords)
	counts := map[string]int{}
	maxLen := 0
	maxLenWord := ""
	for {
		word := nextString()
		if word == "" {
			break
		}

		counts[word]++

		if len(word) > maxLen {
			maxLen = len(word)
			maxLenWord = word
		}
	}

	mapPairs := []Pair{}
	for k, v := range counts {
		mapPairs = append(mapPairs, Pair{k, v})
	}
	sort.Slice(mapPairs, func(i, j int) bool { return mapPairs[i].value > mapPairs[j].value })

	fmt.Println(mapPairs[0].key, maxLenWord)
}

C++: //include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <queue>
#include <iterator>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int gcd(int a, int b){
   int tmp;
   while(a%b==0){
      tmp=a%b;
      a=b;
      b=tmp;
   }
}

int lcm(int a,int b){
   return a*b/gcd(a,b);
}

bool prime_number(int n){
   vector<bool> i;
   if(n < 2){
      return false;
   }
   else if(n == 2){
      return true;
   }
   if(n % 2 == 0){
      return false;
   }
   for(int i=3;i<=n/i;i+=2){
      if(n % i == 0) return false;
      return true;
   }
}

int main(){
   vector<string> s;
   string a,ans1,ans2;
   int tmp, f=0, l=0;
   while(cin>>a) s.PB(a);
   REP(i,s.size()){
      tmp=count(ALL(s),s[i]);
      if(f<tmp){
         f=tmp;
         ans1=s[i];
      }
      if(l<s[i].size()){
         l=s[i].size();
         ans2=s[i];
      }
   }
   cout << ans1 << " " << ans2 << endl;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>

using namespace std;

int main(){
	
	string str[2000];
	
	int n;
	
	n = 10;
	
	for(int i = 0; i < 1000; i++){
		cin >> str[i];
		if(cin.eof()){
			n = i + 1;
			break;
		}
	}
	
	int max_size, max_num, sum, ans_size, ans_num;
	
	max_size = 0;
	max_num = 0;
	
	for(int i = 0; i < n; i++){
		if(str[i].size() > max_size){
			ans_size = i;
			max_size = str[i].size();
		}
		
		sum = 0;
		
		for(int j = 0; j < n; j++){
			if(str[i] == str[j]){
				sum++;
			}
		}
		
		if(sum > max_num){
			max_num = sum;
			ans_num = i;
		}
	}
	
	cout << str[ans_num] << " " << str[ans_size] << endl;
	
	return 0;
}

C++: #include <string.h>
#include <string>
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <utility>

#define ll (long lon
#define REP(i,n) for(int i = 0;i<(int)n;i++)
#define FOR(i,a,b) for(int i = (a);i < (b);i++)
#define RFOR(i,a,b) for(int i = (a);i>(b);i--)
#define INT_MIN -999999
using namespace std;

int main (void){
    
    char str[1000];
    gets(str);
    char tango[500][33];
    int i = 0,j = 0,k = 0,l = 0, temp = 0,m = 0;
    char max[33];
    int max_l = INT_MIN;
    int max_numer = 0;
    int yokuderu = 0;
    int yokuderu_temp = 0;
    int yokuderu_number = 0;
    while(str[i++] != '\0')
    {
        if(str[i-1] == ' ')
        {
            if((i-1)-temp>max_l)
            {
                max_l = (i-1) -temp;
                max_numer = j;
            }
            while(temp<i-1)
                tango[j][l++] = str[temp++];
            temp = i;
            j++;
            l = 0;
        }
    }
    
 
        if((i-1)-temp>max_l)
        {
            max_l = (i-1) -temp;
            max_numer = j;
        }
        while(temp<i-1)
            tango[j][l++] = str[temp++];
        temp = i;
        j++;
        l = 0;
    /*???????????§??????????????????*/
    //cout <<"number is " << j << endl;
    
    for(int m = 0; m < j;m++)
    {
        for(int k = 0; k<j;k++)
        {
            if(m != k)
            {
                if(strcmp(tango[m], tango[k]) == 0)
                {
                    yokuderu_temp++;
                }
            }
        }
        if(yokuderu_temp >= yokuderu)
        {
            yokuderu = yokuderu_temp;
            yokuderu_number = m;
        }
        yokuderu_temp = 0;
    }
    REP(i,32)
    cout << tango[yokuderu_number][i];
    cout << " ";
    while(tango[max_numer][m++] != '\0')
        cout << tango[max_numer][m-1];
    m = 0;
        cout << endl;
    
    
    return 0;
}

C++: #include<iostream>
#include<string>
#include<map>
using namespace std;
int main(){
  map<string,int> word;
  string s,ans_a,ans_b;
  int con_a = 0,con_b = 0;
  while(cin >>s){
    word[s]++;
  }
  map<string,int>::iterator pos;
  for(pos = word.begin(); pos != word.end(); pos++){
    if(pos->second > con_a){con_a = pos->second; ans_a = pos->first;}
    if((pos->first).size() > con_b){con_b = (pos->first).size(); ans_b = pos->first;}
  }
  cout <<ans_a<<" "<<ans_b<<endl;
  return 0;
}

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

using namespace std;

#define int long long
#define PB push_back
#define PPB pop_back
typedef pair<int, int> pii;
static const int INF = 1LL<<61;

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

  string ans1, ans2, in;
  map<string, int> gedo;
  while (cin >> in) {
    if (ans2.size() < in.size()) ans2 = in;
    gedo[in]++;
  }

  int tm = 0;
  for (auto it = gedo.begin(); it != gedo.end(); ++it)
    if (tm < (*it).second) {
      ans1 = (*it).first;
      tm = (*it).second;
    }

  cout << ans1 << " " << ans2 << endl;

  return 0;
}

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

int main() {
	string str[1001], tmp;
	int max_num = 0, max_length = 0, i, max = 1, max_str = 0, a[1001] = {};
	
	while (cin >> tmp) {
		for (i = 0; i < tmp.size(); i++) {
			if ('A' <= tmp[i] && tmp[i] <= 'Z')
				tmp[i] = tmp[i] + 'a' - 'A';
		}

		for (i = 0; i < max; i++) {
			if (str[i] == tmp) {
				a[i]++;
				if (max_str < a[i]) {
					max_str = a[i];
					max_num = i;
				}
				if (tmp.size() > max_length)
					max_length = (int)tmp.size();
				break;
			}
		}
		if (i >= max) {
			str[i-1] = tmp;
			max++;
			a[i - 1]++;
			if (max_str < a[i-1]) {
				max_str = a[i - 1];
				max_num = i - 1;
			}
			if (tmp.size() > max_length)
				max_length = (int)tmp.size();
		}
	}
	cout << str[max_num];

	for (i = 0; i < max; i++) {
		if ((int)str[i].size() == max_length)
			cout <<" "<< str[i] << endl;
	}
	return 0;
}