#abc084b
import sys

a,b=map(int,raw_input().split())
s=raw_input()
if s[a] != '-':
 print 'No'
 sys.exit()
for i in xrange(a):
 if s[i].isdigit()==False:
  print 'No'
  sys.exit()
for i in xrange(a+1,a+1+b):
 if s[i].isdigit()==False:
  print 'No'
  sys.exit()
print 'Yes'
