#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>

int main(int argc, char *argv[]){
	int n;
	std::cout<<"Enter the number of candles."<<std::endl;
	std::cin>>n;
	std::vector<int> c;
	std::cout<<"Enter the lengths of the candles."<<std::endl;
	int temp;
	while(n--){
		std::cin>>temp;
		c.push_back(temp);
	}
	int no_of_days=0;
	while(!c.empty()){
		if(c.size()>no_of_days){
			no_of_days++;
			std::sort(c.begin(), c.end(), std::greater<int>());
			std::transform(c.begin(), c.begin()+no_of_days, c.begin(), 
				std::bind2nd(std::minus<int>(), 1) );
			c.erase(std::remove(c.begin(), c.end(), 0), c.end());
		}else{
			break;
		}
	}
	std::cout<<"No. of days the event can go on = "<<no_of_days<<std::endl;
}

/*
Sample Run :
rahul@kodersbox:~/Desktop$ ./candles
Enter the number of candles.
6
Enter the lengths of the candles.
2 4 5 3 5 1
No. of days the event can go on = 5
*/