const int maxn = 1e5 + ;

 int n, a, Next[maxn];

 char str[maxn];

 bool mark[];

 int main() {

     read(n);

     rep(i, , n) {

         read(a);

         Next[i] = i - a;

     }

     str[] = 'a';

     for (int i = , j = ; i <= n; j = Next[i++]) {

         if (Next[i] == j + ) {

             str[i] = str[j + ];

         } else {

             init(mark, );

             do {

                 mark[str[j + ] - 'a'] = true;

                 if (!j)    break;

                 j = Next[j];

             } while (Next[i] != j + );

             rep(k, , ) if (!mark[k]) {

                 str[i] = 'a' + k;

                 break;

             }

         }

     }

     printf("%s\n", str + );

     return ;

 }