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#include <bits/stdc++.h>
using namespace std;

const long long inf=1e17;
/*
for a,b where a was the (i-1)th number
1. If b is greater than a - nothing happens, b is the next a and a.len is the length of b
2. If b is a prefix of (a+1), a+1 is the next a and a.len is the length of (a+1)
3. If b extended to the length of a is greater than a, b is the next and a.len stays the same
4. If none of the above work, output b extended past a by one zero
*/

long long extend(long long a,long long pot)
{
    while(a<pot)
    {
        a*=10;
    }
    return a;
}

bool ispref(long long a,long long pot,long long b,long long pot2)
{
    pot2/=pot;
    if(b/pot2==a)
        return true;
    return false;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n,i,j;
    long long last2,last_pot2,last=0,curr,last_pot=1,curr_pot,curr_len,last_len=1,last_len2,ans=0;
    cin>>n;
    for(i=0;i<n;i++)
    {
        cin>>curr;
        curr_pot=1;
        curr_len=1;
        if(curr>last)
        {
            while(curr_pot*10<=curr)
            {
                curr_pot*=10;
                curr_len++;
            }
        }
        else
        {
            while(curr_pot*10<=curr)
            {
                curr_pot*=10;
                curr_len++;
            }
            last2=last+1;
            last_pot2=last_pot;
            last_len2=last_len;
            if(last_pot2*10<=last2)
            {
                last_pot2*=10;
                last_len2++;
            }
            if(ispref(curr,curr_pot,last2,last_pot2))
            {
                curr=last2;
                curr_pot=last_pot2;
                ans+=last_len2-curr_len;
                curr_len=last_len2;
            }
            else
            {
               curr=extend(curr,last_pot);
               curr_pot=last_pot;
               if(curr>last)
               {
                    ans+=last_len-curr_len;
                    curr_len=last_len;
               }
               else
               {
                    ans+=last_len-curr_len+1;
                    curr_len=last_len+1;
                    if(curr_pot<inf)
                    {
                        curr*=10;
                        curr_pot*=10;
                    }
               }
            }
        }
        last=curr;
        last_pot=curr_pot;
        last_len=curr_len;
    }
    cout<<ans;
}