use std::env;

extern "C" {
    fn c_func(input: i32) -> i32;
}

fn c_call(i:i32) -> i32{
   unsafe {
    return c_func(i);
    }
}

fn main() {
   let args: Vec<String> = env::args().collect();
   match args[1].parse::<i32>() {
   	 Ok(i) =>  println!("Absolute value of {} is {}",i, c_call(i)),
	 Err(..) => println!("Wrong argument {}",args[1]),
	 };
    
}