#include <bits/stdc++.h>
int main() {
  int a, b;
  scanf("%d %d", &a, &b);
  int size = a + b + 1;
  char s[100];
  scanf("%s", s);
  int i, check;
  for (i = 0; i < size; i++) {
    if (s[a] == '-') {
      check = 1;
    }
  }
  int check2;
  if (check == 1) {
    for (i = 0; i < a; i++) {
      if (s[i] >= '0' && s[i] <= '9') {
        check2 = 2;
      }
    }
  }
  int check3;
  if (check2 == 2) {
    for (i = a + 1; i < size; i++) {
      if (s[i] >= '0' && s[i] <= '9') {
        check3 = 3;
      }
    }
  }
  if (check3 == 3) {
    printf("Yes\n");
  } else {
    printf("No\n");
  }
  return 0;
}
