import re
a, b = map(int, input().split())
s = input()
p1 = "\d{"+ str(a) +"}"
p2 = "\d{"+ str(b) +"}"
if s[a] == "-" and re.fullmatch(p1, s[0:a]) != None and re.fullmatch(p2, s[a+1:]) != None:
        print("Yes")
else:
        print("No")

