#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <stack>
#include <queue>
#include <functional>
#include <limits.h>
#include <set>
#include <map>
#include <tuple>
using namespace std;

#define ll long long
#define ull unsigned long long
#define rep(i,N) for (int i=0;i<N;i++)
#define loop(i,N,M) for(int i=N;i<M;i++)
#define MAX(v) *max_element(v.begin(),v.end())
#define MIN(v) *min_element(v.begin(),v.end())
#define SORTL2S(type,v) sort(v.begin(),v.end(),greater<type>())
#define SORTS2L(type,v) sort(v.begin(),v.end())
#define SORTMF(v,func) sort(v.begin(),v.end(),func)

//変数
ll A,B;
string S;
vector<ll> vec;


//解法
void solve() {
  
  bool flag = true;
  
  rep(i,A) {
    if (S[i]<'0' || S[i]>'9') flag=false;
  }
  if (S[A]!='-') flaag = false;
  rep(i,B) {
    if (S[A+1+i]<'0' || S[A+1+i]>'9') flag = false;
  }
  
  cout << (flag ? "Yes" : "No");
  
	return;
}

int main() {
	//入力

	cin >> A>>B>>S;

	solve();
	cout << endl;
	return 0;
}
