use std::io::*;
const MOD: i64 = 1000000007;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let mut a: i64 = itr.next().unwrap().parse::<i64>().unwrap();
    let mut b: i64 = itr.next().unwrap().parse::<i64>().unwrap();

    // -A <= x+y <= A
    // -B <= x-y <= B
    // -A-y <= x <= A-y
    // -B+y <= x <= B+y
    // max(-A-y,-B+y) <= x <= min(A-y,B+y)
    // -A-y=-B+y -> y=(-A+B)/2, x=(-A-B)/2 - bottom
    // A-y=B+y -> y=(A-B)/2, x=(A+B)/2 - top
    // -B+y=A-y -> y=(A+B)/2, x=(A-B)/2 - right
    // -A-y=B+y -> y=(-A-B)/2, x=(-A+B)/2 - left
    if a == 0 && b == 0 {
        println!("1");
    } else if a == 0 {
        println!("{}", b);
    } else if b == 0 {
        println!("{}", a);
    } else {
        let mut sub = 0;
        if (a & 1) ^ (b & 1) == 1 {
            sub = 1;
        }
        a %= MOD;
        b %= MOD;
        println!(
            "{}",
            (MOD + (a + 1) * (b + 1) % MOD + a * b % MOD - sub) % MOD
        );
    }
}