#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main() {
    char name[20];
    scanf("%s", name);
    
    int valid = 1;
    for (int i = 0; i < strlen(name); i++)
{
        if (!isalpha(name[i])) {
            valid = 0;
            break;
        }
    }
     
    if (!valid) {
        printf("Invalid input");
    } else {
        for (int i = 1; i <= strlen(name));
             printf("%c", name[j]);
        }
        printf("\n");
    }
    }
    return 0;
}