text: #include <iostream>
  #include <cmath>
  #include <algorithm>
  #include <vector>
  using namespace std;
  int main() {
      int A, B; string S; cin >> A >> B >> S;
      for (int i = 0; i < S.length(); ++i) {
          if (i != A) {
              if (S[i] == '-') {
                  printf("%s\n", "No");
                  return 0;
              }
          }
          else {
              if (S[i] != '-') {
                  printf("%s\n", "No");
                  return 0;
              }
          }
      }
      printf("%s\n", "Yes");
      return 0;
  }
  