text: #include <stdio.h>
  
  
  int myatoi(const char s[]) {
      int i, n;
  
      n = 0;
      for (i = 0; s[i] >= '0' && s[i] <= '9'; ++i) {
          printf("%d\n", n);
          n = 10 * n + (s[i] - '0');
      }
      return n;
  }
  
  int main() {
      printf("%d\n", myatoi("1234"));
      return 0;
  }
  