/*
 * This simple program is created by Roland Hollós (hollorol@rolandhollos.net)
 * It is works like this: 
* ez itt egy nagyon hosszu valtozo == ez_itt_egy_nagyon_hosszu_valtozo_
 */
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define MAX_LINE_LEN 10000

int 
main()
{
    char s[MAX_LINE_LEN];
    char out[MAX_LINE_LEN];

    while(fgets(s, MAX_LINE_LEN, stdin) != NULL){
        int string_length = strlen(s);
        for(int i = 0; i < string_length; ++i)
        {
            /* if((s[i] >= 65) && (s[i] <= 90)) */
            if(s[i] == ' '){
                out[i] = '_';
                continue;
            }

            if((s[i] >= 65) && (s[i] <= 90))
            {
                out[i] = s[i] + 32;
            }
            out[i] = s[i];

        }
        out[string_length] = '\0';
        printf("%s", out);
    }
    return 0;
}