#include<bits/stdc++.h>
using namespace std;
#define yes "Yes"
#define no "No"

string solve(int A, int B, string S) {
  bool answer = true;
  if ((A>=1) && (B<=5) && (S[A]=='-')) {
    for (int i=0; i<(A+B+1); i++) 
  	  if (!(('0'=<S[i]) && (S[i]=<'9')) && (i!=A))
  		answer &= false;
  } else
    answer = false;
  
  return (answer) ? yes : no;
}

int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  cout << solve(A, B, S) << endl;
}
