#include<iostream>
#include<sstream>
//i'm flattered by the fact that i'll receive full feedback on this. warms my heart, i tell you 
// : " )  <--  me blushing

int main(){
	std::stringstream result;
	int totalNumbers, aNumber, anotherOne;
	std::cin >> totalNumbers;
	if(totalNumbers == 0){
		std::cout<< "1-100";
		return 0;
	}
	std::cin >> aNumber;
	
	if(aNumber>=2) //dirty hacks ahoy.
		result<< "1-" << aNumber-1<< "\n";
	anotherOne = aNumber; 
	for(int counter = 1; counter < totalNumbers; counter++){
		std::cin >> aNumber;
		if(aNumber - anotherOne > 1)
			result<< anotherOne+1 << "-" << aNumber-1<< "\n";
		anotherOne = aNumber;
	}
	if(anotherOne <= 99)
		result << anotherOne + 1 << "-100"; //the rare doublehack in full effect
	std::cout << result.str();
}