#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  char a[100];
  int x, y, s = 1;
  scanf("%d %d", &x, &y);
  scanf("%s", a);
  int len = strlen(a);
  if (len == x + y + 1 && a[x] == '-') {
    for (int i = 0; i < len; i++) {
      if (a[i] >= '0' && a[i] <= '9') s = 1;
      if (i == x)
        continue;
      else {
        s = 0;
        break;
      }
    }
    if (s == 1)
      printf("Yes\n");
    else
      printf("No\n");
  } else
    printf("No\n");
  return 0;
}
