Modify function to include paragraphs - php

Question

I have this excerpt function that cuts the content after the first paragraph (after the first </p> tag.
I need to modify this so I can cut the content after the second or third paragraph, that is the second or third </p> tag. My knowledge of php is not great, so any help will be appreciated.
Here is my function
if ( ! function_exists( 'wpse0001_custom_wp_trim_excerpt' ) ) :
function wpse0001_custom_wp_trim_excerpt($wpse0001_excerpt) {
global $post;
$raw_excerpt = $wpse0001_excerpt;
if ( '' == $wpse0001_excerpt ) {
$wpse0001_excerpt = get_the_content('');
$wpse0001_excerpt = strip_shortcodes( $wpse0001_excerpt );
$wpse0001_excerpt = apply_filters('the_content', $wpse0001_excerpt);
$wpse0001_excerpt = substr( $wpse0001_excerpt, 0, strpos( $wpse0001_excerpt, '</p>' ) + 4 );
$wpse0001_excerpt = str_replace(']]>', ']]>', $wpse0001_excerpt);
$excerpt_end = ' ' . ' » ' . sprintf(__( 'Read more about: %s »', 'pietergoosen' ), get_the_title()) . '';
$excerpt_more = apply_filters('excerpt_more', ' ' . $excerpt_end);
//$pos = strrpos($wpse0001_excerpt, '</');
//if ($pos !== false)
// Inside last HTML tag
//$wpse0001_excerpt = substr_replace($wpse0001_excerpt, $excerpt_end, $pos, 0);
//else
// After the content
$wpse0001_excerpt .= $excerpt_end;
return $wpse0001_excerpt;
}
return apply_filters('wpse0001_custom_wp_trim_excerpt', $wpse0001_excerpt, $raw_excerpt);
}
endif;
remove_filter('get_the_excerpt', 'wp_trim_excerpt');
add_filter('get_the_excerpt', 'wpse0001_custom_wp_trim_excerpt');
EDIT
This is the section of code I need to modify, but not sure how
$wpse0001_excerpt = substr( $wpse0001_excerpt, 0, strpos( $wpse0001_excerpt, '</p>' ) + 4 );

Answer 1

$wpse0001_excerpt = "<p>1</p><p>2</p><p>3</p><p>4</p><p>5</p>";
$wanted_number_of_paragraph = 3;
$tmp = explode ('</p>', $wpse0001_excerpt);
for ($i = 0; $i < $wanted_number_of_paragraph; ++$i) {
if (isset($tmp[$i]) && $tmp[$i] != '') {
$tmp_to_add[$i] = $tmp[$i];
}
}
$wpse0001_excerpt = implode('</p>', $tmp_to_add) . '</p>';
echo $wpse0001_excerpt;
// Output : <p>1</p><p>2</p><p>3</p>