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