use std::fs;

fn main() {
    let data4 = fs::read_to_string("/home/sky/Documents/4.txt").unwrap();//expect("Unable to read file"); исправил на unwrap
    println!("{}", data4);
    let data5 = fs::read_to_string("/home/sky/Documents/5.txt").expect("Unable to read file");
    println!("{}", data5);

//Ниже что я пробовал.

//    fs::write("/home/sky/Documents/1", data4).expect("Unable to write file");
//	  print!("{}", data4);
//	data4.push_str(&data5);
//	println!("{}", data4);
//	fs::write("/home/sky/Documents/1", data4).expect("Unable to write file");

//	data5.push_str(&data4);
//	println!("{} + {} = {}\n", data4, data5, data4 + data5);
}