Balancing the Scales

Chef loves playing with stones so he discovered a very interesting game. Chef has three weighing scales and $X$ identical stones weighing $1$ gram each. Chef starts placing stones on the weighing scales in random order. After some time, he observes that the scales read $a, b$ and $c$ grams respectively and he has $N$ more stones left with him. Help the Chef find out if he can make the weight