#include <iostream>
#include <utility>

void bar()
{

}

template <class Head, class ... Tail>
void bar(Head head, Tail ... tail)
{
    std::cout « head « std::endl;
    bar(tail ...);
}

template <size_t ... Args>
void foo(std::integer_sequence<size_t, Args ...> seq, int off)
{
    bar((Args + off) ...);
}

int main()
{
    foo(std::make_index_sequence<500>(), 1);
    foo(std::make_index_sequence<499>(), 501);
}

#include "stdio.h"
#include "math.h"

char *nta(unsigned int count, unsigned int number)
{
  
  int i;
  char *numberArray = calloc(count, sizeof(char));
  for ( i = 0; i < count; ++i, number /= 10 ) {
    numberArray[i] = number % 10;
  }
  return numberArray;
}

int main()
{

  unsigned int N, i = 0, c = 0, j = 0, count = 0;

  char *n = NULL;

  scanf("%u", &N);

  while (i++ < pow(10, N)) {
    
    if (n != NULL)
      free(n);
        
        count = log10(i) + 1;
        
    n = nta(count, i);
    
    if (i < 10) {
      c++;
      continue;
    }

    for (j = 0; j < count - 1; j++) {
      if (n[j] != n[j + 1])
        c++;
    }
  }

  printf("c = %u\n", c);

  return 0;
}