ARGS check

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
int main(int argc, char **argv) {
  char *p;
  int a, b;
  if (argc != 3) exit(1);
  for (p = argv[1]; *p; p++) if (!isdigit(*p)) exit(1);
  for (p = argv[2]; *p; p++) if (!isdigit(*p)) exit(1);
  a = atoi(argv[1]);
  b = atoi(argv[2]);
  if (100 < a || 100 < b) exit(1);
  printf("argv[1]: %d, argv[2]: %d\n", a, b);
  return 0;
}