Give the IUPAC name of the following alkenes :
`CH_2 = CH - CH = CH_2`

Explanation

To determine the IUPAC name of the given alkene `CH2 = CH - CH = CH2`, we can follow these steps:

### Step 1: Identify the longest carbon chain
The given structure has four carbon atoms connected by double bonds. The longest continuous chain of carbon atoms is four carbons long.

### Step 2: Number the carbon chain
We need to number the carbon chain such that the double bonds receive the lowest possible numbers. Starting from the left:
1. C1: CH2
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