#include <iostream>
using namespace std;

int main(){
  int A,B,lp,Ar= 0;
  char S[11];
  int flag = 0;

  cin >> A >> B;

  cin >> S[];

  lp = 0;
  while (lp < A+B+1){
    if (S[lp] = '0'or'1'or'2'or'3'or'4'or'5'or'6'or'7'or'8'or'9'){
      if (flag == 0){
        Ar++;
      }
    }else{
      if (lp == A+1 and S[lp] == '-'){
        flag++;
      }
    }
    lp ++;
  }

  //処理
  if (Ar == A){
    cout << "Yes"<<endl;
  }else{
    cout << "No"<<endl;
  }
