#include <bits/stdc++.h>
char S[11];
int main(void) {
  int step = 0;
  int A, B;
  scanf("%d%d", &A, &B);
  fflush(stdin);
  scanf("%s", S);
  for (int i = 0; i < A + B + 1; ++i) {
    if (('0' > S[i] || S[i] > '9') && (S[i] != '-')) {
      printf("No\n");
      return 0;
    }
    switch (step) {
      case 0:
        if ('0' <= S[i] && S[i] <= '9') {
          step++;
        } else {
          printf("No\n");
          return 0;
        }
        break;
      case 1:
        if (S[i] == '-') {
          step++;
        }
        break;
      case 2:
        if ('0' <= S[i] && S[i] <= '9') {
          step++;
        } else if (S[i] == '-') {
          printf("No\n");
          return 0;
        }
        break;
      case 3:
        if ('0' > S[i] && S[i] > '9') {
          printf("No\n");
          return 0;
        } else if (S[i] == '-') {
          printf("No\n");
          return 0;
        }
        break;
    }
  }
  if (step != 3)
    printf("No\n");
  else
    printf("Yes\n");
  return 0;
}
