A,B=map(int,input().split())
S=input()
number=0
list=['0','1','2','3','4'.'5','6','7','8','9']
for a in range(A):
    if S[a] in list:
        number+=1
if S[A]=='-':
    number+=1
for a in range(B):
    if S[A+a+1] in list:
        number+=1
if number==A+B+1:
    print('Yes')
else:
    print('No')
