a,b,c=map(str,input().split())
a=float(a)
b=float(b)
if c!="-":
    if c!="+":
        if c!="/":
            if c!="*":
                print("Invalid operator!")
            else:
                print(a*b)
        else:
            if b==0:
                print("Divided by zero!")
            else:
                if a/b<0:
                    d=int(a/b)
                    print(d+1)
                else:
                    d=int(a/b)
                    print(d-1)
    else:
        print(a+b)
else:
    print(a-b)