#include <bits/stdc++.h>
int main() {
  int a, b, i, len, t;
  char s[100];
  while (scanf("%d %d", &a, &b) != EOF) {
    getchar();
    gets(s);
    len = strlen(s);
    t = 0;
    if (len != a + b + 1) {
      printf("No\n");
    } else {
      if (s[a] != '-') {
        printf("No\n");
      } else {
        for (i = 0; i < len; i++) {
          if (i == a) {
            i++;
          }
          if (s[i] == '0' || '1' || '2' || '3' || '4' || '5' || '6' || '7' ||
              '8' || '9') {
            t++;
          }
        }
        if (t == len - 1) {
          printf("Yes\n");
        } else
          printf("No\n");
      }
    }
  }
  return 0;
}
