Apple jam sliced

Wash the apples, dry them, cut out the cores, cut into slices 5-8 mm wide.
Take a 1.5 liter saucepan, put the apples there in layers, sprinkling each layer with sugar. And leave them for 12 hours to let the juice.
Then bring the jam to a boil and, turning down the heat, cook for 5 minutes, trying not to stir the jam, but simply drown the apples in syrup with a spoon, pressing on top of them. So the slices will not lose shape.
Remove the pan from the stove, cover it with a towel and leave for 12 hours. Then repeat the cooking in the same way as before - until boiling, cook for 5 minutes. And leave it for another 12 hours. After cooking the jam for 10-15 minutes. Jam hot twist in jars.