import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.stdio;
import std.string;
import std.range;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

bool calc(int sx, int sy) {
    bool rec(int x, int y, int step) {
        if (x == sx && y == sy)
            return true;
        if (step == 3)
            return false;

        foreach (dx; [1, 2]) {
            foreach (dy; [1, 2]) {
                if (dx == dy)
                    continue;

                foreach (s1; [1, -1]) {
                    foreach (s2; [1, -1]) {
                        int x2 = x + (dx * s1);
                        int y2 = y + (dy * s2);

                        if (rec(x2, y2, step + 1))
                            return true;
                    }
                }
            }
        }
        return false;
    }

    return rec(0, 0, 0);
}

void main() {
    auto xy = readints();
    int x = xy[0], y = xy[1];
    writeln(calc(x, y) ? "YES" : "NO");
}