#include <stdio.h>
#include <string.h> // For strlen
#include <ctype.h>  // For isalnum

int main() {
    int n;
    scanf("%d", &n);

    char batches[100]; // Assuming max batch name length is 99 characters
    int invalid_input = 0;

    for (int i = 0; i < n; i++) {
        scanf("%s", batches[i]);
        for (int j = 0; j < strlen(batches[i]); j++) {
            if (!isalnum(batches[i][j])) {
                invalid_input = 1;
                break;
            }
        }
        if (invalid_input) {
            break;
        }
    }

    if (invalid_input) {
        printf("Invalid input\n");
    } else {
        for (int i = 0; i < n; i++) {
            printf("%s", batches[i]);
            if (i < n - 1) {
                printf(" ");
            }
        }
        printf("\n");
    }

    return 0;
}