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

s =input()

intlist = ["0","1","2","3","4","5","6","7","8","9"]

for i in range(a):
    if s[i] in intlist:
        pass
    else:
        print("No")
        exit()

if s[a] != "-":
    print("No")
    exit()
    
for j in range(a+1,a+1+b):
    if s[i] in intlist:
        pass
    else:
        print("No")
        exit()

print("Yes")