#include<bits/stdc++.h>

using namespace std;

int main()

{

int n;

cin>>n;

vector<char> str(n);

for (int i = 0; i < n; ++i)

cin >> str[i];

int sum = 0,speed = 0;

for(int i = 0;i < n;i++)

{

if(str[i] == '0')

{

speed += 10;

sum += speed;

}

if(str[i] == '1')

{

speed -= 5;

if(speed < 0) speed = 0;

sum += speed;

}

if(str[i] == '2')

{

int temp = speed;

speed = max(0, speed - 10);

sum += speed;

speed = temp;

}

}

cout<<sum<<endl;

return 0;

}