# a,b=input().split(':')
# print(a,b,sep=':')
# a,b,c=input().split(':')
# print(b)
#a,b=input().split()
#c=int(a)+int(b)
# print(c)
# a=input()
# print(a,a,a)
# a=input()
# b=input()
# c=float(a)+float(b)
# print(c)
# format(c,".2f")
a,b=input().split(' -')
c=int(a)-int(b)
print(c)
