#include <stdio.h>
/*ripped off the internet; that's why it's so elegant*/
main (){
    int c;
    while ((c = getchar()) != EOF) {
        if (c == ' ') {
            while ((c = getchar()) == ' ');
            putchar(' ');
            if (c == EOF) break;
        }
        putchar(c);
    }
}