#include<stdio.h>
#include<stdlib.h>

int lencln(char const * sin){
    int len = 0;

    for (int i = 0; sin[i] != '\0'; i++)
    {
        if(sin[i] >= 'A' && sin[i] <= 'Z' || sin[i] >= 'a' && sin[i] <= 'z'){
            len++;
        }
    }

    return len;
}

char * clean(char const * sin){
    int j = 0;
    char * str_cln = NULL;

    str_cln = (char*)malloc(sizeof(char) * (lencln(sin) + 1));

    if(!str_cln){
        fprintf(stderr, "Out of memory!\n");
        exit(-10);
    }

    for (int i = 0; sin[i] != '\0'; i++)
    {
        if(sin[i] >= 'A' && sin[i] <= 'Z' || sin[i] >= 'a' && sin[i] <= 'z'){
            str_cln[j] = sin[i];
            j++;          
        }
    }

    return str_cln;
}

int main(){
    char sin[101];

    scanf(" %100[^\n]s", sin);

    char * strout = clean(sin);    

    printf("%s\n", strout);

    free(strout);
    strout = NULL;

    return 0;
}