#include <bits/stdc++.h>
int main() {
  int a, b;
  bool printTrue = true;
  bool printNo = true;
  scanf("%d %d", &a, &b);
  char str[a + b + 1];
  scanf("%s", &str);
  for (int i = 0; str[i] != '\0'; i++) {
    if (str[i] >= '0' && str[i] <= '9' || str[i] == '-') {
      if (str[a] == '-') {
        printTrue = true;
        break;
      }
      if (str[a] != '-') {
        printNo = true;
        break;
      }
    }
  }
  if (printTrue) {
    printf("Yes\n");
  }
  if (printNo) {
    printf("No\n");
  }
  return 0;
}
