#include <iostream>
#include <vector>
#include <string>
using namespace std;

#ifndef _CGIINPUT_H
#define _CGIINPUT_H

class CGIinput
{
public:
    CGIinput() 
    {
        string input;
        cin >> input;

        if (cin) {
            input = URLdecode(input) + "&";

            while (input != "") {
                int equalPos = input.find("=");
                int ampPos = input.find("&");

                elements.push_back(input.substr(0, equalPos));
                values.push_back(input.substr(equalPos+1, ampPos-equalPos-1));

                input = input.substr(ampPos+1, input.length());
            }
        }
    }

    int NumElements()
    {
        return elements.size();
    }

    string Element(int index)
    {
        return elements[index];
    }

    string Value(int index)
    {
        return values[index];
    }

    string ElementValue(string desiredElement)
    {
        for (int i = 0; i < elements.size(); i++) {
            if (elements[i] == desiredElement) {
                return values[i];
            }
        }
        return "NOT FOUND";
    }

private:
    vector<string> elements;   // the names of the elements from the page
    vector<string> values;     // the corresponding values for the elements

    string URLdecode(string input)
        // precondition : input string is URLencoded
        // postcondition: returns decoded string
    {
        string clean = "";
        for (int i = 0; i < input.length(); i++) {
            if (input[i] == '+') {
                clean += ' ';
            } 
            else if (input[i] == '%') {
                const string digits = "0123456789ABCDEF";
                clean += (char)(digits.find(input[i+1])*16 + digits.find(input[i+2]));
                i += 2;
            } 
            else {
                clean += input[i];
            }
        }
        return clean;
    }
};

#endif