#include "stdio.h"
#include "stdlib.h"
#include "string.h"

char* string();

int main() {

	printf("%s", string());

	return 0;
}

char* string() {
	char input[128];
	printf("enter a word: ");
	scanf(input, "%s");
	int counter = 0;
	char temp[128];
	int i = 0;
	while (i < input[i]) {
		if ('a' <= input[i] && input[i] <= 'z') {
			temp[counter] = input[i];
			counter++;
		}
		else if ('A' <= input[i] && input[i] <= 'Z') {
			temp[counter] = input[i]+32;
			counter++;
		}
		else if (input[i] == '.' || input[i] == ',' || input[i] == '?' || input[i] == '!') {
			temp[counter] = input[i];
			counter++;
		}
		i++;
	}
	char* output = (char*)malloc(counter * sizeof(char));
	i = 0;
	while (i < counter) {
		*(output + i) = temp[i];
		i++;
	}
	*(output + counter) = '\0';


	return output;
}