A, B = map(int, input().split())
S = input()
x=0
if S[A+1-1]=='-':
    for i in set(S)-{'-'}:
        if i not in ('0','1','2','3','4','5','6','7','8','9'):
            x=0
        else:
            x=1
else:
    x=0
if x==0:
    print('No')
elif x==1:
    print('Yes')
