#include <iostream>
#include <list>
#include <ctype.h>
 
int main(){
	std::list<int> balls;
	int n, ball, curr;
	bool cheater;
 
	std::cin >> n;
 
	while(!std::cin.eof()){
		std::cin >> ball;
		balls.push_back(ball);
	}
 
	cheater = false;
	std::list<int>::iterator it = balls.begin();
	while(it != balls.end()){
		std::cout << *it << " ";
		curr = *it;
		if(curr >= *(++it)) cheater = true;
		std::cout << "curr = " << curr << ", it = " << *it << std::endl;
		curr = *it;
		//it++;
	}
 
	if(cheater)
		std::cout << "Cheater";
	else
		std::cout << "Not a proof";
}

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NCAxIDMgNCA1IDc=

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