if __name__ == '__main__':
    A, B = map(int,input().split())
    S = input()
    S_size = len(S)
    S1 = S[0:A]
    S2 = S[A+1:S_size-1]
    S_ = S[A]

    if S1.isdecimal() == True:
        judge1 = True
    else:
        judge1 = False

    if S2.isdecimal() == True:
        judge2 = True
    else:
        judge2 = False

    if S_ == '-':
        judge3 = True
    else:
        judge3 = False

    if judge1 == True and judge2 == True and judge3 == True:
        print("Yes")
    else:
        print("No")
