#include<stdio.h>
#include<string.h>
int main()
{
  int n;
  char S[100],T[100]="\0";
  scanf("%d",&n);
  scanf("%s",S);
  strncat(T,S,n);
  if(strlen(S)>n)
    strcat(T,"...");
  printf("%s\n",T);
  return 0;
}
