/* folds long input lines into two or more shorter lines after the
 * last non-blank character that occurs before the n-th column of
 * input, handling very long lines and blank-less lines intelligently
 */

#include <stdio.h>

#define MAXLINE 20
#define TABSPC 8

#define putbuf buf[bufi] = '\0'; \
               printf("%s", buf); \
               buf[0] = '\0'; \
               bufi = 0;

int main(void) {
     char buf[MAXLINE+1];
     int i, c, bufi, t1, t2;

     i = bufi = 0;
     buf[0] = '\0';
     while ((c=getchar()) != EOF) {
	  if (i >= MAXLINE) {
	       if (bufi < MAXLINE) {
		    putchar('\n');
		    i = bufi;
	       } else if (bufi > MAXLINE) {
		    t2 = buf[--bufi];
		    t1 = buf[--bufi];
		    putbuf;
		    printf("-\n");
		    buf[bufi++] = t1;
		    buf[bufi++] = t2;
		    i = bufi;
	       }
	  }
	  if (c == ' ') {
	       putbuf;
	       putchar(c);
	       i++;
	  } else if (c == '\t') {
	       putbuf;
	       putchar(c);
	       i += TABSPC;
	  } else if (c == '\n') {
	       putbuf;
	       putchar(c);
	       i = 0;
	  } else {
	       buf[bufi++] = c;
	       i++;
	  }
     }

     if (bufi > 0) putbuf;

     return 0;
}