```python
def best_harvest(yields: list) -> int:
    if not isinstance(yields, list):
        raise ValueError("Input must be a list")
    
    if not all(isinstance(y, int) and y >= 0 for y in yields):
        raise ValueError("All yields must be non-negative integers")
    
    total = 0
    for i in range(len(yields)):
        total += yields[i]
        while i + 1 < len(yields) and yields[i] == yields[i + 1]:
            i += 1
    
    return total
```