import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
MD2 = lambda d1,d2: [[INIT_VAL]*d2 for _ in range(d1)]
MD3 = lambda d1,d2,d3: [MD2(d2,d3) for _ in range(d1)]
## math
DIVC = lambda x,y: -(-x//y)
DIVF = lambda x,y: x//y

def main():
    a, b = MII()
    s = IS()
    d = {'1','2','3','4','5','6','7','8','9','0'}
    for i in range(a):
        if s[i] not in d:
            print('No')
            return None
    if s[a] != '-':
        print('No')
        return None
    for i in range(a+1,a+b+1):
        if s[i] not in d:
            print('No')
    print('Yes')

if __name__ == '__main__':
    main()