Given Reactions:
Correct Answer: The correct answer is 3.
\[ \text{CH}_3\text{COONa} \longrightarrow \cdot \text{CH}_3 \]
\[ \text{C}_2\text{H}_5\text{COONa} \longrightarrow \cdot \text{C}_2\text{H}_5 \]
\[ 2 \cdot \text{C}_2\text{H}_5 \longrightarrow \text{CH}_3 - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]
\[ 2 \cdot \text{CH}_3 \longrightarrow \text{CH}_3 - \text{CH}_3 \]
\[ \cdot \text{CH}_3 + \cdot \text{C}_2\text{H}_5 \longrightarrow \text{CH}_3 - \text{CH}_2 - \text{CH}_3 \]
Complete the following reactions by writing the structure of the main products: 
Let R = {(1, 2), (2, 3), (3, 3)}} be a relation defined on the set \( \{1, 2, 3, 4\} \). Then the minimum number of elements needed to be added in \( R \) so that \( R \) becomes an equivalence relation, is: