#include <bits/stdc++.h>
int main(void) {
  int a, b;
  char s[100];
  int s2;
  int flag = 0;
  scanf("%d %d", &a, &b);
  scanf("%s", &s);
  if (s[a] == '-') {
    if (s[a + b + 1] == '\0') {
      for (int i = 0; i < a; i++) {
        if (s[i] >= '0' && s[i] <= '9')
          flag = 1;
        else {
          flag = 0;
          break;
        }
      }
      for (int i = a + 1; i < a + b + 1; i++) {
        if (s[i] >= '0' && s[i] <= '9')
          flag = 1;
        else {
          flag = 0;
          break;
        }
      }
    }
  }
  if (flag == 1)
    printf("Yes");
  else
    printf("No");
  return 0;
}
