use proconio::input;

fn main() {
  
  let mut _n : usize ;
  let mut _d : String ;
 

  

    input! {
     
      mut n : usize ,
      mut d : String ,
    }

     let  length = d.len();

      if length > n{
        let s = &d[0..n];
      println!("{}...",s);

     }else   {

      println!("{}",d);

     }

   
    
}

