package main

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

type FastScanner struct {
	r *bufio.Reader
}

func NewFastScanner() *FastScanner {
	return &FastScanner{r: bufio.NewReaderSize(os.Stdin, 1<<20)}
}

func (fs *FastScanner) nextInt64() int64 {
	var sign int64 = 1
	var val int64 = 0
	c, _ := fs.r.ReadByte()
	for (c < '0' || c > '9') && c != '-' {
		c, _ = fs.r.ReadByte()
	}
	if c == '-' {
		sign = -1
		c, _ = fs.r.ReadByte()
	}
	for c >= '0' && c <= '9' {
		val = val*10 + int64(c-'0')
		c, _ = fs.r.ReadByte()
	}
	return val * sign
}

func max3(a, b, c int64) int64 {
	if a < b {
		a = b
	}
	if a < c {
		a = c
	}
	return a
}

func main() {
	fs := NewFastScanner()
	out := bufio.NewWriterSize(os.Stdout, 1<<20)
	defer out.Flush()

	t := int(fs.nextInt64())
	for ; t > 0; t-- {
		n := int(fs.nextInt64())
		a := make([]int64, n)
		for i := 0; i < n; i++ {
			a[i] = fs.nextInt64()
		}
		var sumPos2, sumPos3 int64
		for i := 1; i < n; i++ {
			if a[i] > 0 {
				sumPos2 += a[i]
			}
		}
		for i := 2; i < n; i++ {
			if a[i] > 0 {
				sumPos3 += a[i]
			}
		}
		var a1 int64
		if n > 0 {
			a1 = a[0]
		}
		ans := max3(0, sumPos3, a1+sumPos2)
		fmt.Fprintln(out, ans)
	}
}