#include <iostream>
#include <map>
#include <functional>

using namespace std;

class DFA {
public:
    bool simulation(std::string& input, const std::map<char, std::function<void()>>& symbol_reaction(), const std::map<const std::string, std::function<void()>>& start_reaction(), const std::map<const std::string, std::function<void()>>& end_reaction()) {

        string currentState = "3";
        for (auto ch : input) {

            if (currentState == "1") {
                start_reaction.at("1")();
                if (ch == 48)
                {
                    currentState = "1";
                    symbol_reaction[48];
                }
                if (ch == 49)
                {
                    currentState = "2";
                    symbol_reaction.at(49)();
                }
                end_reaction.at("1")();
            }
            if (currentState == "2") {
                start_reaction.at("2")();
                if (ch == 48)
                {
                    currentState = "2";
                    symbol_reaction.at(48)();
                }
                if (ch == 49)
                {
                    currentState = "3";
                    symbol_reaction.at(49)();
                }
                end_reaction.at("2")();
            }
            if (currentState == "3") {
                start_reaction.at("3")();
                if (ch == 48)
                {
                    currentState = "3";
                    symbol_reaction.at(48)();
                }
                if (ch == 49)
                {
                    currentState = "1";
                    symbol_reaction.at(49)();
                }
                end_reaction.at("3")();
            }
        }

        bool isFinalState = false;

        if (currentState == "1") {
            isFinalState = false;
        }
        if (currentState == "2") {
            isFinalState = false;
        }
        if (currentState == "3") {
            isFinalState = true;
        }
        return isFinalState;
    }
};

int main() {

    DFA example;
    example.simulation();

    return 0;
}