#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main(void)
{
    char name[50];
    fgets(name, sizeof(name), stdin);
    int len = strlen(name);
    if(len > 0 && name[len- 1] =='\n') {
        name[len - 1] = '\0';
        len--;
    }
    
    if (len < 1 || len > 10)  {
        printf("Invalid input");
        return 0;
    }
    for (int i = 0; i < len; i++) {
        if (!isalpha((unsigned char)name[i]) && name[i] != ' ') {
            printf("Invalid input");
            return 0;
        }
}
    for (int i = 0; i <= len; i++) {
    for (int j = 0; j < i; j++) {
        printf("%c", name[j]);
    printf("\n");
    }