#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef long double LD;
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define sortAndUnique(a) sort((a).begin(), a.end()), (a).erase(unique((a).begin(), (a).end()),(a).end())

double tick() {
	static clock_t oldticks;
	clock_t newticks = clock();
	double diff = 1.0 * (newticks - oldticks) / CLOCKS_PER_SEC;
	oldticks = newticks;
	return diff;
}

#define DEBUG

#ifdef DEBUG

    #define debug(args...)     (Debugger()) , args

    class Debugger
    {
        public:
        Debugger(const std::string& _separator = " - ") :
        first(true), separator(_separator){}

        template<typename ObjectType> Debugger& operator , (const ObjectType& v)
        {
            if(!first)
                std:cerr << separator;
            std::cerr << v;
            first = false;
            return *this;
        }
        ~Debugger() {  std:cerr << endl;}

        private:
        bool first;
        std::string separator;
    };

#else
    #define debug(args...)                  // Just strip off all debug tokens
#endif

int main(void) {

  cerr << tick();		//Prints execution time on error screen
}