n,k=map(int,input().split())
if n%k==0:
    print(0)
else:
    print(n%k) n,k=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split k if n%k==0:
    print(0)
else:
    print(n%k) n%k==0 n%k n k 0 print(0) print 0 print(n%k) print n%k n k k=map(int,input().split()) map(int,input().split()) k n,k=map(int,input().split()) map(int,input().split()) n
n,k=map(int,input().split())
if n%k==0:
    print(0)
else:
    print(n%k)