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

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

string solve() {
  	int i, j=0;
    if ((S[A] == '-') && ( 1 <= A ) && ( B <= 5 ) && (sizeof(S) == (A+B+2)))
      for (i=0; i<(A+B+1); j+= (int)(('0'<=S[i]) && (S[i]<='9')); i++);

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

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

