```go
package main

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

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var t int
	fmt.Fscan(in, &t)
	for i := 0; i < t; i++ {
		var n int
		fmt.Fscan(in, &n)
		var maxVal, lastVal int
		for j := 0; j < n; j++ {
			fmt.Fscan(in, &lastVal)
			if j < n-1 {
				if lastVal > maxVal {
					maxVal = lastVal
				}
			}
		}
		fmt.Fprintln(out, maxVal+lastVal)
	}
}
```