#include <stdio.h>

short isNotEqual(char tmpChar, char* usedChars) {
	for (int i = 0; i < strlen(usedChars); i++)
		if (usedChars[i] == tmpChar)
			return 0;
	return 1;
}

void findEqualElem(char* str) {
	char tmpChar;
	int counter = 0;
	char usedChars[50];
	for (int i = 0; i < strlen(str); i++) {
		tmpChar = str[i];
		for (int j = i + 1; j < strlen(str); j++)
			if (tmpChar == str[j] && (isNotEqual(tmpChar, usedChars) == 1))
				counter++;
		if (counter > 0)
			for (int j = 0; j <= counter; j++)
				printf("%c", tmpChar);
		counter = 0;
		usedChars[i] = tmpChar;
	}
}

int main() {
	printf("Enter the string: ");
	char str[80];
	gets(str);
	findEqualElem(str);
}