#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;
}