You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: b_test.go
    path of file: ./repos/codeforces-go/misc/atcoder/arc119/b
    
    the code of the file until where you have to start completion: // Code generated by copypasta/template/atcoder/generator_test.go
package main

import (
	"github.com/EndlessCheng/codeforces-go/main/testu
    
func Test_run(t *testing.T) {
	t.Log("Current test is [b]")
	testCases := [][2]string{
		{
			`7
1110110
1010111`,
			`2`,
		},
		{
			`20
11111000000000011111
11111000000000011111`,
			`0`,
		},
		{
			`6
111100
111000`,
			`-1`,
		},
		{
			`119
10101111011101001011111000111111101011110011010111111111111111010111111111111110111111110111110111101111111111110111011
11111111111111111111111111011111101011111011110111110010100101001110111011110111111111110010011111101111111101110111011`,
			`22`,
		},
		
	}
	testutil.AssertEqualStringCase(t, testCases, 0, run)
}