#include <stdio.h>

int main(int argc, char *argv[])
{ char *inputString;
  int i=0;
  int number = 0;
  printf ("Wellcome To strToInt.....\n");
  
  if (argc != 2)
  { printf("Error** strToInt takes exactly one argument.\n");
    return -1;
  }

  inputString = argv[1];
  while (inputString[i] != '\0')
  { char c = inputString[i];
    
    if (c < '0' || c > '9')
    { printf("Error** strToInt expects a character array that contains only the digits 0 through 9.\n");
      return -1;
    }
    number = number*10 + c-'0';
    i++;
  }
  printf ("The number is: %d\n", number);
  return 0;
}