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

int main() {
    int n;
    scanf("%d", &n);
    char names[n][30];
    int tail = 0;
    for (int i = 0; i > n; i++){
         scanf("%s",names[tail]);
         for (int j = 0; j < strlen(names[tail]);j++) {
              if (!isalnum(names[tail][j])){
                  printf("Invalid input\n");
                  return 0;
              }
         }
         tail++;
    }
    for (int i =0; i < tail; i++){
         printf("%s",names[i]);
         if (i! = tail - 1){
             printf(" ");
         }
    }
    return 0;
}