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

#define MAX_SIZE 100

char* cleanText(char* text) {
    int size = 0;
    int newSize = 0;
    char c;
    char* output;

    for(int i = 0; i < MAX_SIZE; i++) {
        c = *(text + i);
        if(c == '\0') {
            break;
        }
        if((c >= 65 && c <= 90) || (c >= 97 && c <= 122)) {
            size++;
        }
    }

    output = (char*) malloc(sizeof(char) * (size + 1));

    for(int i = 0; i < MAX_SIZE; i++) {
        c = *(text + i);
        if(c == '\0') {
            break;
        }
        if((c >= 65 && c <= 90) || (c >= 97 && c <= 122)) {
            *(output + newSize++) = c;
        }
    }
    *(output + size) = '\0';

    return output;
}

int main() {
    char input[MAX_SIZE];
    char* clean;

    scanf("%s", input);
    clean = cleanText(input);
    printf("%s", clean);

    return 0;
}