#include <stdio.h>

#define BUFSIZE 5242880

int main( argc, argv )
  int argc;
  char *argv[];
{
    char buffer[BUFSIZE], digitstr[64];
    char *bufptr, *numptr;
    int nread, i;

    numptr = digitstr;

    while (( nread = fread( buffer, 1, BUFSIZE, stdin )) > 0 ) {
        bufptr = buffer;
        i = 0;
        while ( i < nread ) {
            if ( *bufptr >= 0x30 && *bufptr <= 0x39 )
                *numptr++ = *bufptr;
            else if ( numptr > digitstr ) {
                *numptr = 0;
                printf( "%s\n", digitstr );
                numptr = digitstr;
            }
            bufptr++;
            i++;
        }
    }
/* update: need this list bit in case last char in the stream is a digit */
    if ( numptr > digitstr ) {
        *numptr = 0;
        printf( "%s\n", digitstr );
    }
}