#include <stdio.h>
#include <string.h>
#include <ctype.h>

int isValidName(const char *name) {
    for (int i = 0; name[i]; ++i) {
        if (!isalpha(name[i]) && !isspace(name[i]))
            return 0; // Contains special character
    }
    return 1;
}

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

    char names[n][101];
    int tail = 0; // tail keeps track of the end of the "queue"
    int invalid = 0;

    for (int i = 0; i < n; ++i) {
        fgets(names[tail], sizeof(names[tail]), stdin);
        names[tail][strcspn(names[tail], "\n")] = 0; // Remove newline
        if (!isValidName(names[tail])) invalid = 1;
        tail++; // Move tail forward for each name added
    }

    if (invalid) {
        printf("Invalid input\n");
    } else {
        for (int i = 0; i < tail; ++i) {
            printf("%s", names[i]);
            if (i < tail - 1) printf(" "); // Print space if not last
        }
        printf("\n");
    }
    return 0;
}