const DIVISIOR: u64 = 1_000_000_007;

fn power(base: u64, p: u64) -> u64 {
    if p == 0 { return 1u64; }
    if p == 1 { return base; }
    let temp: u64 = power(base, p / 2u64);
    temp * temp % DIVISIOR * power(base, p % 2) % DIVISIOR
}

fn comb(n: u64, r: u64, nums: &Vec<u64>, dens: &Vec<u64>) -> u64 {
    nums[n as usize] * dens[n as usize - r as usize] % DIVISIOR * dens[r as usize] % DIVISIOR
}

fn main() {
    let mut nm = String::new();
    std::io::stdin().read_line(&mut nm).ok();
    let nm: Vec<u64> = nm.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nm[0];
    let m = nm[1];

    let mut nums: Vec<u64> = vec![1; m as usize + 1usize];
    let mut dens: Vec<u64> = vec![1; m as usize + 1usize];
    for i in 1..=m {
        nums[i as usize] = nums[i as usize - 1usize] * i;
        nums[i as usize] %= DIVISIOR;
        dens[i as usize] = dens[i as usize - 1usize] * power(i, DIVISIOR-2);
        dens[i as usize] %= DIVISIOR;
    }
    let result: u64 = (n..=m)
        .map(|i| comb(i, n, &nums, &dens))
        .sum()
    ;
    println!("{}", result % DIVISIOR);
}