#include <bits/stdc++.h>
int main() {
  int a, b, i = 0, check = 0;
  char moji[12];
  scanf("%d", &a);
  scanf("%d", &b);
  scanf("%s", moji);
  for (i = 0; i < a; i++)
    if (isdigit(moji[i]) == 1) check++;
  if (moji[a] == '-') check++;
  for (i = a + 1; i < a + b + 1; i++)
    if (isdigit(moji[i]) == 1) check++;
  if (check == a + b + 1)
    printf("Yes");
  else
    printf("No");
  return 0;
}
