#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main(){
    char name[12];
    fgets(name, 12, stdin);
    name[strcspn(name, "\n")] = 0;
    for (int i=0;name[i]; i++){
        if(isdigit(name[i])){
            printf("Invalid input\n");
            return 0;
        }
}
if (strlen(name) == 0){
    printf("Invalid input\n");
}else{
    for (int i =1;i <= strlen(name); i++){
        printf("% .*s\n", i, name);
    }
}
return 0;
}