#include<iostream>
#include<string>

using namespace std;

int main()
{
    int n;
    string bodovi;
    cin>>n;
    string rj;
    for(int a=0; a<n; ++a)
    {
            cin>>bodovi[a];
    }
    for(int b=1; b<n; ++b)
    {
            if(bodovi[b-1]>bodovi[b])
            {
                                     rj[b]=bodovi[b-1]-bodovi[b];
                                     rj[b]=rj[b] + 1;
            }
            else if(bodovi[b] == bodovi[b-1])
            {
                 rj[b]=bodovi[b] - 1;
            }
            else if(bodovi[b]>bodovi[b-1])
            {
                 rj[b]=0;
            }
    }
    for(int c=1; c<n; ++c)
    {
            rj=rj+rj[c];
    }
    cout<<rj<<endl;
}