# include <bits/stdc++.h>
using namespace std;
int main()
{
 int a[15],money=0,shengyu=0,mam=0,fu=0;
	for(int i=1;i<=12;i++)
	{
		money=shengyu+300;
		cin>>a[i];
		if(money-a[i]<0)
		{
			fu=1;
			cout<<-i;
			break;
		}
		else
		{
			mam+=(money-a[i])/100*100;
			shengyu=(money-a[i])%100;
		}
	}
	if(fu==0)cout<<mam*120/100;
}