```go
package main

import "fmt"

func main() {
	var t int
	fmt.Scan(&t)
	for i := 0; i < t; i++ {
		var l, r int
		fmt.Scan(&l, &r)
		n := r - l + 1
		odd := (r+1)/2 - l/2
		ans := n / 3
		if odd/2 < ans {
			ans = odd / 2
		}
		fmt.Println(ans)
	}
}
```