A,B =map(int,input().split())
hih=0
num=1
JG=1
S=int(input())
S= list(str(S))
for s in S:
    if s=="-":
        hih=num 
    num+=1
for s in S:
    if s=="0" or s=="1" or s=="2" or s=="3" or s=="4" or s=="5" or s=="6" or s=="7" or s == "8" or s=="9":
    else:
        JG=0
if hih==A & JG==1:
    print("Yes")
else:
    print("No")