#include <iostream>
using namespace std;
int main()
{
	int x,temp(0),save(0);
	for(int i=1;i<=12;i++)
	{
		cin>>x;
		temp+=300-x;
		if(temp<0)
		{
			cout<<-i<<endl;
			return 0;
		}
		if(temp/100)
		{
			save+=(temp/100)*100;
			temp-=temp-temp%100;
		}
	}
	cout<<save*1.2+temp<<endl;
	return 0;
}
/**************************************************************
	Problem: 2248
	User: admin
	Language: C++
	Result: Accepted
	Time:49 ms
	Memory:2072 kb
****************************************************************/