And no one knows who was lucky.

 Who eaten ripe watermelon or sugar melon, or who is a bough bad products, as melon is not aromatic, hard, watermelon is light and not sweet. But such fruits are better matching for jam.

A cutting from a crust of a pulp of melon or watermelon cut on cubes o 1-2 cm, and in watermelons remove seeds. Sprinkle a pulp with sugar and for 2 hours put in cold place, and after cook in sugar syrup are 1.2 kg of sugar for one kg cleaned pulp, not adding water. Cook within 3 methods till boiling, with keeping for 8-10 hours. And before a last cooking add 2-3 gr of lemon acid  and vanilla by taste.