c.go

package main

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

func min(s []byte, k int64) (int, int64) {
	sl := len(s)
	for i := 0; i < sl; i++ {
		if s[i] == 'a' {
			continue
		}
		if int64(('z'+1)-s[i]) <= k {
			diff := 'z' + 1 - s[i]
			s[i] = 'a'
			return i, k - int64(diff)
		}
	}
	s[sl-1] += byte(k % 26)
	return -1, 0
}

func main() {
	in := bufio.NewReader(os.Stdin)
	s, _ := in.ReadString(byte('\n'))
	s = s[:len(s)-1]
	kstr, _ := in.ReadString(byte('\n'))
	kstr = kstr[:len(kstr)-1]
	k, _ := strconv.ParseInt(kstr, 10, 64)
	b := []byte(s)
	i := 0
	for k > 0 {
		var v int
		v, k = min(b[i:], k)
		i += v
	}
	fmt.Println(string(b))
}