@sukaoleg123, it looks like the source you used needed to be upscaled which has led to a loss of quality in the eventual cut. Choosing the best and biggest source available ensures that your cuts are of the best possible quality, which isn't the case in your cut-out.

Also, the technique for nudging the collar upward that I showed you here needs to be used in cases like this image where the collar is quite low when compared to the chin. There should be no more than 2-3 pixels beneath the chin, and every cut must have a collar, which is why that technique is to be followed in all cases when necessary.