    A, B = map(int, input().split())
    S = input()
    C = "1234567890"
    for i in range(len(S)):
        if i == A:
            if S[i] == "-":
                continue
            else:
                print("No")
                exit()
        else:
            if S[i] in C:
                continue
            else:
                print("No")
                exit()
    print("Yes")
    exit()
resolve()