Go: package main

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

func configure(scanner *bufio.Scanner) {
	// scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	for s := getNextString(scanner); s != "END OF INPUT"; s = getNextString(scanner) {
		ss := strings.Split(s, " ")
		for i := 0; i < len(ss); i++ {
			fmt.Fprint(writer, len(ss[i]))
		}
		fmt.Fprintln(writer, "")
	}
}

C++: #include <iostream>
#include <string>

using namespace std;

int main() {
	string b;
	while (getline(cin, b)) {
		if (b == "END OF INPUT") {
			break;
		}
		int counter = 0;
		bool hantei = false;
		for (int i = 0; i < b.size(); i++) {
			if (b[i] == ' ') {
				if (i != 0 && b[i-1] != ' ') {
					cout << counter << flush;
					counter = 0;
				} else if (i != 0){
					hantei = true;
				}
			} else {
				if (hantei) {
					cout << 0 << flush;
					hantei = false;
				}
				counter++;
			}
		}
		cout << counter << endl;
	}
	return 0;
}

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

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) (r).begin(),(r).end()
#define gsort(st,en) sort((st),(en),greater<int>())
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)
#define vvl(v,w,h,init) vector<vector<ll>> v(w,vector<ll>(h,init));

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using dict = map<string,int>;
using pii = pair<int,int> ;
using pll = pair<ll,ll> ;

const int mod = 1000000007;
constexpr int imax = ((1<<30)-1)*2+1 ;
constexpr int inf = 100000000;
constexpr double PI = acos(-1.0) ;
double eps = 1e-10 ;
const int dy[] = {-1,0,1,0,1,-1,1,-1};
const int dx[] = {0,-1,0,1,1,-1,-1,1};

inline bool value(int x,int y,int w,int h){
  return (x >= 0 && x < w && y >= 0 && y < h);
}

template<typename T>
void Unique(vector<T> &v){
  sort(all(v));
  v.erase(unique(all(v)),v.end());
}

template<typename T>
T ston(string& str, T n){
  istringstream sin(str) ;
  T num ;
  sin >> num ;
  return num ;
}

void Ans(bool f){
  if(f) cout << "YES"<<endl;
  else cout << "NO"<<endl;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  string str;
  while(getline(cin,str)){
    if(str == "END OF INPUT") break;
    ll cnt = 0,f = 0;
    rep(i,str.size()){
      if(str[i] != ' '){
        ++cnt;
      }
      else{
        if(cnt || !f){
          cout << cnt;
        }
        f = !f;
        cnt = 0;
      }
    }
    cout << cnt << endl;
  }
  return 0;
}

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

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) (r).begin(),(r).end()
#define gsort(st,en) sort((st),(en),greater<int>())
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)
#define vvl(v,w,h,init) vector<vector<ll>> v(w,vector<ll>(h,init));

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using dict = map<string,int>;
using pii = pair<int,int> ;
using pll = pair<ll,ll> ;

const int mod = 1000000007;
constexpr int imax = ((1<<30)-1)*2+1 ;
constexpr int inf = 100000000;
constexpr double PI = acos(-1.0) ;
double eps = 1e-10 ;
const int dy[] = {-1,0,1,0,1,-1,1,-1};
const int dx[] = {0,-1,0,1,1,-1,-1,1};

inline bool value(int x,int y,int w,int h){
  return (x >= 0 && x < w && y >= 0 && y < h);
}

template<typename T>
void Unique(vector<T> &v){
  sort(all(v));
  v.erase(unique(all(v)),v.end());
}

template<typename T>
T ston(string& str, T n){
  istringstream sin(str) ;
  T num ;
  sin >> num ;
  return num ;
}

void Ans(bool f){
  if(f) cout << "YES"<<endl;
  else cout << "NO"<<endl;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  string str;
  while(getline(cin,str)){
    if(str == "END OF INPUT") break;
    ll cnt = 0,f = 0;
    rep(i,str.size()){
      if(str[i] != ' '){
        ++cnt;
        f = 0;
      }
      else{
        if(!f){
          f = true;
          cout << cnt;
        }
        cnt = 0;
      }
    }
    cout << cnt << endl;
  }
  return 0;
}

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

int main(){
    int count;
    while(1){
        
       count = 0;
       string str;
       getline(cin,str);
       if(str == "END OF INPUT") break;
        for(int i = 0; i < str.length(); i++){
            
            if(str[i] == ' '){
                printf("%d",count);
                count = 0;
                
            }
            else count++;
        }
        printf("%d\n",count);
    }
    return 0;
}

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

int main(){
    string input;
    while(getline(cin, input), input != "END OF INPUT"){

        int num = 0;
        for(int i=0; i < input.size(); i++){
            if(input[i] == ' '){
                cout << num;
                num = 0;
            }
            else {
                num++;
            }
        }
        cout << num<< endl;
    }
}

C++: #define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;

//#define int long long
#define DBG 1
#define dump(o) if(DBG){cerr<<#o<<" "<<o<<endl;}
#define dumpc(o) if(DBG){cerr<<#o; for(auto &e:(o))cerr<<" "<<e;cerr<<endl;}
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define each(it,c) for(auto it=(c).begin();it!=(c).end();it++)
#define all(c) c.begin(),c.end()
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9 + 7);

signed main() {
	string s;
	while (getline(cin, s), s != "END OF INPUT") {
		string ans;
		int cnt('0');
		rep(i, 0, s.size()) {
			if (s[i] == ' ') {
				ans.push_back(cnt);
				cnt = '0';
			}
			else cnt++;
		}
		ans.push_back(cnt);
		cout << ans << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int main() {string s;while (getline(cin, s)) {if (s=="END OF INPUT") return 0;s+=" ";for (int i=0,j=s.length(),cnt=0;i<j;i++) if (s[i]!=' ') cnt++; else if (cnt) cout<<cnt,cnt=0;cout<<endl;}}