a,b=map(int,input().split())
s=input()
y=0
c=[0,1,2,3,4,5,6,7,8,9]
for i in range(a):
    for j in range(len(c)):
        if int(s[i])!=c[j]:
            y+=1
if s[a]!="-":
    y+=1
for i in range(a+1,a+b+1):
    for j in range(len(c)):
        if int(s[i])!=c[j]:
            y+=1
if y!=0:
    print("Yes")
else:
    print("No")