a,b = map(int,input().split())
s = list(input())
num = [str(i) for i in range(10)]
flag = True
for i in range(a+b+1):
    if s[a]!='-':
        flag = False
        
    if 0<=i<a or a+1<=i<b:
        if not s[i] in num:
            flag = False
            
    if i==0:
        if s[i]=='0':
            flag = False
print('Yes' if flag==True else 'No')
