def number(c):
    c = str(c)
    ans = 0
    s = "0123456789"
    for i in range(10):
        if c == s[i]:ans = 1
    return ans

A,B = map(int,input().split())
S = input()
flag = 1
for i in range(A):
    if(number(S[i]) != 1):flag = 0
if S[A] != "-":flag = 0
for j in range(B):
    if(number(S[A+1+i]) != 1):flag = 0
if flag:print("Yes")
else:print("No")
