#include <bits/stdc++.h>
using namespace std;
#define LL long long
//Lab 4
bool isOperator(char ch)
{
    if (ch == '+' || ch == '-' || ch == '*' ||
        ch == '/' ||  ch == '=' ||  ch == '%')
        return true;
    return false;
}

bool isKeyword(string str)
{
    if (str == "if" || str == "else" ||
       str == "while" || str == "do" ||
        str == "break" || str == "continue"||
       str == "int" || str == "double" ||
        str == "float" || str == "return" ||
        str == "char" || str == "case" ||
        str == "char" || str == "sizeof" ||
        str == "long" || str == "switch" ||
        str == "string" || str == "void" ||
        str == "static")

        return true;
    return false;
}

bool isConstant(char str)
{
    if (str == '0' || str == '1' || str == '2' ||
        str == '3' || str == '4' || str == '5' ||
        str == '6' || str == '7' || str == '8' ||
        str == '9')
        return true;
    return false;
}

bool variable(string str)
{
    if(isKeyword(str)) return false;

    if(!((str[0] >= 'A' and str[0] <= 'Z') or (str[0] >= 'a' and str[0] <= 'z') or (str[0] == '_'))) return false;

    for (int i = 1; i < str.size(); i++) {
        if (!((str[i] >= 'a' and str[i] <= 'z') or (str[i] >= 'A' and str[i] <= 'Z')
          or (str[i] >= '0' and str[i] <= '9') or str[i] == '_')) return false;
    }
    return true;
}

void solve(){

   ofstream fout;
   string line,strOpeartor,strKeyword,strConstant,strVariable;
   string temp;
   fout.open("program.txt");

   while (fout) {
        getline(cin, line);

        for(int i=0;i<line.size();i++){
            int op = 1;
            if(isOperator(line[i])){
                for(int j=0;j<strOpeartor.size();j++){
                    if(strOpeartor[j]==line[i]){
                        op = 0;
                    }
                }
                if(op){
                  strOpeartor.push_back(line[i]);
                  strOpeartor.push_back(',');
                }
            }
            if(isConstant(line[i])){
                int co = 1;
                for(int j=0;j<strConstant.size();j++){
                    if(strConstant[j]==line[i]){
                        co = 0;
                    }
                }
                if(co){
                  strConstant.push_back(line[i]);
                  strConstant.push_back(',');
                }
            }
        }

        for(int i=0;i<line.size();i++){

            if(line[i]!=' ') temp+=line[i];

            if(line[i]==' ' or i+1==line.size()){
                if(isKeyword(temp)){
                    strKeyword+=temp+" ";
                }
                if(variable(temp)){
                    strVariable+=temp+" ";
                }
                temp="";
            }
        }

        if (line == ".") break;

    }
    cout<<"Operator: "<<strOpeartor<<"\n";
    cout<<"Keyword: "<<strKeyword<<"\n";
    cout<<"Constant: "<<strConstant<<"\n";
    cout<<"Identifier: "<<strVariable<<"\n";

    fout.close();
}

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