```go
package main

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

func main() {
	in := bufio.NewReaderSize(os.Stdin, 1<<20)
	out := bufio.NewWriterSize(os.Stdout, 1<<20)
	defer out.Flush()

	var t int
	fmt.Fscan(in, &t)
	for i := 0; i < t; i++ {
		var a, b int64
		fmt.Fscan(in, &a, &b)
		d := a - b
		if d < 0 {
			d = -d
		}
		ans := d/5 + (d%5)/2 + (d%5)%2
		fmt.Fprintln(out, ans)
	}
}
```