```go
package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

func main() {
	reader := bufio.NewReader(os.Stdin)
	var t int
	fmt.Fscan(reader, &t)
	for i := 0; i < t; i++ {
		var n int
		var s string
		fmt.Fscan(reader, &n, &s)
		fmt.Println(solve(s))
	}
}

func solve(s string) string {
	n := len(s)
	var sb strings.Builder
	i := 0
	for i < n {
		sb.WriteByte(s[i])
		sb.WriteByte(s[i+1])
		if i+2 < n && !isVowel(s[i+2]) && (i+3 >= n || !isVowel(s[i+3])) {
			sb.WriteByte(s[i+2])
			i += 3
		} else {
			i += 2
		}
		if i < n {
			sb.WriteByte('.')
		}
	}
	return sb.String()
}

func isVowel(c byte) bool {
	return c == 'a' || c == 'e'
}
```