import sys

stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().strip()

a,b = na()
s = ns()
flag = 0
if s[a] == "-":
    s = s.replace("-","")
    for i in s:
        for j in range(10):
            if i == str(j):
                flag = 1
                break
            flag = 0
        if flag == 0:
            break
if flag:
    print("Yes")
else:
    print("No")
