#include <bits/stdc++.h>
int main() {
  int A, B;
  int i = 0;
  int follows = 1;
  char S[13];
  scanf("%d %d\n%s", &A, &B, S);
  while (i < A && follows) {
    if ('0' <= S[i] && S[i] <= '9')
      i++;
    else
      follows = 0;
  }
  if (S[i] != '-') follows = 0;
  i++;
  while (i < B && follows) {
    if ('0' <= S[i] && S[i] <= '9')
      i++;
    else
      follows = 0;
  }
  if (follows)
    printf("Yes\n");
  else
    printf("No\n");
  return (0);
}
