#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>

unsigned int getSum(FILE *file);
char getFirstDigit(const char *line, size_t len);
char getLastDigit(const char *line, size_t len);

int main(int argc, char *argv[]) {

  if (argc != 2) {
    printf("error: missing file input\n");
    return 1;
  }

  FILE *file = fopen(argv[1], "r");
  if (file == NULL) {
    printf("could not open file: %s\n", argv[1]);
    return 1;
  }

  unsigned int sum = getSum(file);
  printf("%d\n", sum);

  fclose(file);

  return 0;
}

unsigned int getSum(FILE *file) {

  unsigned int sum = 0;
  size_t len = 0;
  size_t read;
  char *line = NULL;

  while ((read = getline(&line, &len, file)) != -1) {
    printf("%s", line);
    char first = getFirstDigit(line, read);
    char last = getLastDigit(line, read);
    printf("%c%c\n", first, last);
    char digits[3] = {first, last, '\0'};
    sum += atoi(digits);
  }

  free(line);
  return sum;
}

char getFirstDigit(const char *line, size_t len) {

  char digit;
  for (int i = 0; i < len; i++) {
    if (isdigit(line[i])) {
      digit = (char)line[i];
      break;
    }
  }
  return digit;
}

char getLastDigit(const char *line, size_t len) {

  char digit;
  for (int i = len - 1; i >= 0; i--) {
    if (isdigit(line[i])) {
      digit = (char)line[i];
      break;
    }
  }
  return digit;
}