"use strict"
const create = () => {
    const input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
    const res = {
        "list": input, "index": 0, "max": input.length,
        "hasNext": function () { return this.index < this.max },
        "next": function () { if (!this.hasNext()) { throw "ArrayIndexOutOfBoundsException"; } else { return this.list[this.index++]; } }
    };
    return res;
}
const o = create();
const next = () => o.next()
const nextInt = () => parseInt(o.next())
const nextStrArray = () => o.next().split(" ")
const nextIntArray = () => o.next().split(" ").map(el => parseInt(el))
const nextCharArray = () => o.next().split("")
const hasNext = () => o.hasNext()
const myout = (...x) => console.log(...x)
const Main = () => {
    let [n, m] = next().split(" ").map(el => BigInt(el))
    let ans = 0n
    if (n == 1n && m == 1n) {
        ans = 1n
    } else if (n == 1n && m !== 1n) {
        ans = m - 2n
    } else if (n !== 1n && m == 1n) {
        ans = n - 2n
    } else if (n == 2n || m == 2n) {
        ans = 0n
    } else {
        ans = (n - 2n) * (m - 2n)
    }
    console.log(ans.toString())
}
Main()
