import strutils,sequtils,sets

var
    opt = stdin.readLine.split.map(parseInt)
    S = stdin.readLine

proc isNumber(s:string):bool=
    var num = ['0','1','2','3','4','5','6','7','8','9'].toHashSet
    for c in s:
        if not num.contains(c):
            return false
    return true
if S[0..opt[0]-1].isNumber and S[opt[0]] == '-' and S[opt[0]+1..opt[0]+opt[1]].isNumber:
    echo "Yes"
else:
    echo "No"
