#include <bits/stdc++.h>
bool right();
int main() {
  if (right())
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
bool right() {
  char s[8];
  int a, b;
  scanf("%d%d%s", &a, &b, s);
  if (s[a] != '-') return false;
  for (int i = 0; i < a + b + 1; i++)
    if ((s[i] < '0' || s[i] > '9') && i != a) return false;
  return true;
}
