a, b = map(int, input().split())
s = str(input())
cnt = 0

for i in range(a):
    if int(s[i]) in range(0, 10):
        cnt += 1
if s[a]=='-':
    cnt += 1
for i in range(b):
    if int(s[a+1+i]) in range(0, 10):
        cnt += 1

if cnt == a+b+1:
    print('Yes')
else:
    print('No')