Jelly, 6 bytes

ṀŻ‘ḟ³Ṃ

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Jelly, 6 bytes

ṀŻ‘ḟ³Ṃ

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Explanation

ṀŻ‘ḟ³Ṃ  #                  | [-1, 0, 1, 4]
Ṁ       # Maximum          | 4
 Ż      # Range from 0     | [0, 1, 2, 3, 4]
  ‘     # Increment        | [1, 2, 3, 4, 5]
   ḟ    # Filter out items |
    ³   # In the input     | [2, 3, 5]
     Ṃ  # Minimum          | 2