```go
package main

import "fmt"

func main() {
	var t int
	fmt.Scan(&t)
	for range make([]int, t) {
		var n int
		fmt.Scan(&n)
		var s string
		fmt.Scan(&s)
		bal := 0
		minbal := 0
		for _, c := range s {
			if c == '(' {
				bal++
			} else {
				bal--
			}
			if bal < minbal {
				minbal = bal
			}
		}
		fmt.Println(-minbal)
	}
}
```