#include <stdio.h>
#include <stdint.h>
void remove_duplicates(char *str) {
int dict[1000] = {0};
int write = 0;
int read = 0;
while (str[read] != '\0'){
int sint = str[read];
if (dict[sint]==0){
// first occ.
dict[sint] = 1;
str[write]=str[read];
write++;
read++;
} else {
// already present, advance only read.
read++;
}
}
str[write] = '\0';
}
int main() {
char str[101];
fgets(str, sizeof(str), stdin);
// Remove newline
uint8_t i = 0;
while (str[i]) {
if (str[i] == '\n') {
str[i] = '\0';
break;
}
i++;
}
remove_duplicates(str);
printf("%s", str);
return 0;
}