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

int str_len(const char s[]){
  int len = 0;
  while(s[len])
    len++;
  return len;
}

int main(void){
  int k;
  scanf("%d",&k);
  char s[]="";
  scanf("%s",&s);
  int len = str_len(s);
  if (len<=k){
    printf("%s",s);
  }else{
    char *t = strncpy(t,s,k);
    printf("%s...",t);
  }
  return 0;
}
