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

int A, B;
string S;
#define yes "Yes"
#define no "No"

int check(char c) { return '0' <= c and c <= '9'; }

string solve() {
  	int j = 0
    if (S[A+1] == '-')
      if ( 1 <= A )
        if ( B <= 5)
          for (int i=0; i<(A+B+2) && (sizeof(S) == (A+B+2)); i++)
  		  	if (check(S[i]))
              j++;

  	return (j == (A+B+1)) ? yes : no;
}

int main() {
  cin >> A >> B >> S;
  cout << solve() << endl;
  
  return 0;
}

