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

static void usage(void)
{
	fputs("\
usage: nocrlf <count>\n\
\n\
   Removes all instances of <count> adjacent newlines from stdin.\n\
   For example, to remove all instances of 3 adjacent blank lines:\n\
\n\
      nocrlf 3 <textfile.txt\n\
", stderr);
	exit(-1);
}

void main(int argc, char **argv)
{
	int COUNT;
	int ch, prev='\n';
	int intcount=0;

	if (argc == 1) usage();

	if ((COUNT = atoi(argv[1])) <= 0) usage();

	while ((ch = getchar()) != EOF) {
		if (ch == '\n' && prev == '\n') {
			if (++intcount >= COUNT) {
				intcount = 0;
			}
		} else {
			while (intcount) {
				putchar('\n');
				intcount--;
			}
			putchar(ch);
		}
		prev = ch;
	}
}