Lemons are washed, cut into slices and cleaned of seeds. Mix with lemon juice, vinegar and peeled and stripped of cucumber seed. Grind puree and place in a deep pan. Put it on to boil the mixture. Add pectin, stir 1/2 cup of sugar and 1 cup water. Mix well and allow to boil again, and then pour the remaining sugar. Boil until the mixture under drip on a cold plate, it keeps its shape (no more than 1/2 hour). The finished mixture is packed into heated, sterilized jars. Close and leave to cool down with caps.