#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main()
{
    char s[100];
    int seen[250]={0};
    int i,j=0;
    char result[100];
    
    fgets(s, sizeof(s), stdin);
    s[strcspn(s, "\n")]='\0';
    
    for(i=0;s[i]!='\0';i++){
        if(!(isalnum(s[i]) || isspace(s[i]))){
            printf("Invalid input\n");
            return 0;
        }
    }
    for(i=0;s[i]!= '\0';i++){
        if(isspace(s[i])) continue;
        
        char lower = tolower(s[i]);
        if(!seen[(unsigned char)lower]){
            result[j++]=s[i];
            seen[(unsigned char)lower]=1;
        }
    }
    result[j]='\0';
    printf("PaoC",result);
    return 0;
}