Why does the program output the same number?

Question

C++ / C#

Task:
Find sequences of digits in the string, consider each of them as a number in the number system that corresponds to the maximum digit, replace the numbers in the string with symbols with codes derived from these numbers. Example: aaa010101bbb343ccc - binary and five-digit number systems.
The code:

#include <stdio.h>
#include <math.h>

int funcc(char a[]) {
  int length = strlen(a);
  printf("length = %d\n", length);
  char num[255];
  int w;
  int check = 0;
  for (int i = 0; i < length; i++)
  {
    if (a[i] >= '0' && a[i] <= '9') {
      num[i] = a[i];
      if (i == length - 1) {
        w = atoi(num);
        int secondw = w;
        if (check == 1) {
          printf("w = %d\n", w);
          int a = 0;
          while (w > 0) {
            int b = w % 10;
            if (b > a) {
              a = b;
            }
            w /= 10;
          }
          a++;
          printf("sistema schisleniya = %d\n", a);
          int ssm = 0;
          int u = 0;
          while (secondw > 0) {
            ssm += secondw % 10 * pow(a, u);
            secondw /= 10;
            u++;
          }
          printf("perevod = %d\n\n", ssm);
          check = 0;
        }
      }
      check = 1;
      continue;
    }

    else {
      w = atoi(num);
      int secondw = w;
      if (check == 1) {
        printf("w = %d\n", w);
        int a = 0;
        while (w > 0) {
          int b = w % 10;
          if (b > a) {
            a = b;
          }
          w /= 10;
        }
        a++;
        printf("sistema schisleniya = %d\n", a);
        int ssm = 0;
        int u = 0;
        while (secondw > 0) {
          ssm += secondw % 10 * pow(a, u);
          secondw /= 10;
          u++;
        }
        printf("perevod = %d\n\n", ssm);
        check = 0;
      }
      continue;
    }
  }
}

int main()
{
  char mas[19] = "010101bbbccc53534";
  funcc(mas);
}

But for some reason, the function outputs only the first number of the array, so the answer is:
length = 17
w = 10101
sistema schisleniya = 2
perevod = 21

w = 10101
sistema schisleniya = 2
perevod = 21