a,b = map(int,input().split())
s=list(input())

c = 0
for i in range(0,a):
    if s[i] == '0' or s[i] == '1' or s[i] == '2' or s[i] == '3' or s[i] == '4' or s[i] == '5'or s[i] == '6' or s[i] == '7' or s[i] == '8' or s[i] == '9':
        c = c+1
if s[a] == '-':
    c = c + 1
for i in range(0,b):
     if s[i] == '0' or s[i] == '1' or s[i] == '2' or s[i] == '3' or s[i] == '4' or s[i] == '5'or s[i] == '6' or s[i] == '7' or s[i] == '8' or s[i] == '9':
        c = c+1
if c == a+b+1:
    print('Yes')
else:
    print('No')