/*input
4 3 3
2 3 1 1
*/

#include <bits/stdc++.h>
using namespace std;

#define fill(a,val) memset(a, (val), sizeof a)
#define pb push_back
#define lli long long int
#define endl "\n"
#define unique(x) x.erase(unique(x.begin(),x.end()), x.end())
#define      rep(i, n)         for(int i = 0; i < (n); ++i)
#define      FOR(i, a, n)     for(int i = a; i < (n); ++i)
#define      repD(i, a, n)     for(int i = a; i >= (n); --i)

int main(void)
{
  int a,b ; cin>>a>>b;
  string s; cin>>s;
  bool p=true;
  for(int i=0; i<a; ++i){
    if(!(s[i]>='0' and s[i]<='9')){
        p=flase;
    }
  }
  if(arr[a]!='-') p=false;
  for(int i=0; i<b; ++i){
    if(!(s[a+1+i]>='0' and s[a+i+1]<='9')){
        p=flase;
    }
  }
  if(p) cout<<"Yes";
  else cout<<"No";
  return 0;
}
