```go
package main

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

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

	var t int
	fmt.Fscan(reader, &t)

	a := make([]int, 4)
	for i := 0; i < t; i++ {
		fmt.Fscan(reader, &a[0], &a[1], &a[2], &a[3])
		sort.Ints(a)
		fmt.Fprintln(writer, a[0]*a[2])
	}
}
```