#include<stdio.h>
#include<string.h>
#include<ctype.h>

int main() {
    char symbols[100] = {0};
    char result[100] = {0};
    int lenght;

    gets(symbols);

    lenght = (int) strlen(symbols);

    int lenght2 = lenght + lenght/3;

    result[lenght2 --]=0;

    int counter=1;

    for(int i=lenght-1; i>=0; i--)
    {
        result[lenght2--]=symbols[i];
        if(counter % 3 == 0)

            result[lenght2--]=' ';
            counter++;

    }
    printf("%s", result);

    return 0;
}