#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<(int)(n);i++)
#define fs first
#define sc second
typedef pair<ll, ll> l_l;
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
int main(){
  int a,b;
  cin>>a>>b;
  string s;
  cin>>s;
  bool f=false;
  if(s[a]=='-')f=true;
  bool b=false;
  for(int i=0;i<a;i++)if(0<=s[i]-'0'&&s[i]-'0'<=9)b=true;
  bool d=false;
  for(int i=a+1;i<a+b+1;i++)if(0<=s[i]-'0'&&s[i]-'0'<=9)d=true;
  if(f&&b&&d)
  cout <<"Yes"<<endl;
  else cout<<"No"<<endl;
}