You went shopping to buy cakes and donuts with X yen (the currency of Japan).  First, you bought one cake for A yen at a cake shop. Then, you bought as many donuts as possible for B yen each, at a donut shop.  How much do you have left after shopping?
x,a,b = [int(input()) for i in range(3)]
print(x - (a+(b//2)*b) )
x,a,b = [int(input()) for i in range(3)]
print(x - (a+((x-a)//b)*b) )