l = input().split()
s = input()
c = list(s)
b = True
for i in range(int(l[0])):
    if not (c[i] >= '0' and c[i] <= '9'):
        b = b and False
if not (c[int(l[0])] is '-'):
    b = b and False
for i in range(int(l[1])):
    if not (c[int(l[0]) + 1 + i] >= '0' and c[int(l[0]) + 1 + i] <= '9'):
        b = b and False
if b:
    print("Yes")
else:
    print("No")