def solve():
    A,B = map(int,input().split())
    S = input()
    seq = [str(x) for x in range(10)]
    print(seq)

    for i in range(A+B+1):
        if i== A:
            if S[i] != "-":
                return False
        else:
            if not(S[i] in seq):
                return False
    return True

if __name__ == '__main__':
    cond = solve()
    if cond:
        print("Yes")
    else:
        print("No")