pub use __cargo_equip::prelude::*; use input_i_scanner::InputIScanner; fn main() { let stdin = std::io::stdin(); let mut _i_i = InputIScanner::from(stdin.lock()); macro_rules! scan { (($($t: ty),+)) => { ($(scan!($t)),+) }; ($t: ty) => { _i_i.scan::<$t>() as $t }; (($($t: ty),+); $n: expr) => { std::iter::repeat_with(|| scan!(($($t),+))).take($n).collect::>() }; ($t: ty; $n: expr) => { std::iter::repeat_with(|| scan!($t)).take($n).collect::>() }; } let (_n, m) = scan!((u64, u64)); // (1 + 2 + 4 + ... + 2^(m-1)) / 2 let p = 1_000_000_000 + 7; let ans = (mod_pow(2, m, p) + p - 1) % p * 500000004 % p; println!("{}", ans); } fn mod_pow(a: u64, x: u64, m: u64) -> u64 { if x == 0 { 1 } else if x == 1 { a % m } else if x % 2 == 0 { mod_pow(a * a % m, x / 2, m) } else { a * mod_pow(a, x - 1, m) % m } } // The following code was expanded by `cargo-equip`. /// # Bundled libraries /// /// - `input_i_scanner 0.1.0 (git+https://github.com/ia7ck/rust-competitive-programming#b60dc67706797611e680510aa6492f6397a2e104)` licensed under **missing** as `crate::__cargo_equip::crates::input_i_scanner` #[cfg_attr(any(), rustfmt::skip)] #[allow(unused)] mod __cargo_equip { pub(crate) mod crates { pub mod input_i_scanner {use std::fmt;use std::io;use std::str;pub struct InputIScanner{r:R,l:String,i:usize,}implInputIScanner{pub fn new(reader:R)->Self{Self{r:reader,l:String::new(),i:0,}}pub fn scan(&mut self)->T where T:str::FromStr,::Err:fmt::Debug,{self.skip_blanks();assert!(self.i{self.i+=j;break;}None=>{let mut buf=String::new();let num_bytes=self.r.read_line(&mut buf).unwrap_or_else(|_|panic!("invalid UTF-8"));assert!(num_bytes>0,"reached EOF :(");self.l=buf.trim_end_matches('\n').trim_end_matches('\r').to_string();self.i=0;}}}}}impl<'a>From<&'a str>for InputIScanner<&'a[u8]>{fn from(s:&'a str)->Self{Self::new(s.as_bytes())}}impl<'a>From>for InputIScanner>>{fn from(stdin:io::StdinLock<'a>)->Self{Self::new(io::BufReader::new(stdin))}}} } pub(crate) mod macros { pub mod input_i_scanner {} } pub(crate) mod prelude {pub use crate::__cargo_equip::crates::*;} mod preludes { pub mod input_i_scanner {} } }