class Solution {
public:
    bool reachingPoints(int sx, int sy, int tx, int ty) {
        while (tx >= 0 && ty >= 0)
        {
            if (tx < sx || ty < sy)return false;
            if (ty > tx)
            {
                ty %= tx;
                if (tx == sx && sy > ty && (sy - ty) % tx == 0)return true;
            }
            else
            {
                tx %= ty;
                if (ty == sy && sx > tx && (sx - tx) % ty == 0)return true;
            }
        }
        return false;
    }
};