Problem:
Score : 400 points

Problem Statement

Mr. Takahashi has a string s consisting of lowercase English letters.
He repeats the following operation on s exactly K times.

Choose an arbitrary letter on s and change that letter to the next alphabet. Note that the next letter of z is a.

For example, if you perform an operation for the second letter on aaz, aaz becomes abz.
If you then perform an operation for the third letter on abz, abz becomes aba.

Mr. Takahashi wants to have the lexicographically smallest string after performing exactly K operations on s.
Find the such string.

Constraints

1≤|s|≤10^5

All letters in s are lowercase English letters.

1≤K≤10^9

Input

The input is given from Standard Input in the following format:

s
K

Output

Print the lexicographically smallest string after performing exactly K operations on s.

Sample Input 1

xyz
4

Sample Output 1

aya

For example, you can perform the following operations: xyz, yyz, zyz, ayz, aya.

Sample Input 2

a
25

Sample Output 2

z

You have to perform exactly K operations.

Sample Input 3

codefestival
100

Sample Output 3

aaaafeaaivap

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define SaveTime ios_base::sync_with_stdio(false);cin.tie(NULL);
#define pb push_back 
#define eb emplace_back
#define mx *max_element
#define mi *min_element
#define fn for(int i =0 ;i <n;i++)
#define fn1 for( int i =1;i<=n;i++)
#define fm for(int j =0 ;j <m;j++)
#define fm1 for(int j =1;j<=m;j++)
#define fi first
#define se second
#define MOD 1000000007
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
const int N = 1e6+5;
const int INF = 1e18L;
int ncr(int n,int r){if(n<r)return 0;int p=1,k=1;if(n-r<r)r=n-r;if(r!=0){while(r){p*=n;k*=r;int g=__gcd(p, k);p/=g;k/=g;n--;r--;}}else p=1;return p;}
#define pi acos(-1)
int ar[N];
int tree[2*N];
int dp[N];
int bit[N];
signed main(){
 	// #ifndef ONLINE_JUDGE
 	// freopen("input.txt","r",stdin);
 	// freopen("output.txt","w",stdout);
 	// #endif
	SaveTime;
	int T=1;
	// cin >> T;
	while(T--){
		string s;
		cin >> s;
		int k;
		cin >> k;
		int n = s.size();
		int i =0 ;
		while(i < n && k){
			int c = s[i]-'a';
			if(c){
				if( k >=26-c){
					s[i]='a';
					k-=(26-c);
				}
			}
			i++;
		}
		for(int i = n-1; k>0 && i >=0;i--){
			while(k){
				s[i] = (char)(s[i]+ 1);
				--k;
				if(s[i]=='z'){
					--k;
					s[i] = (char)(s[i]+ k%26);
					k=0;
					break;
				}
			}
		}
		cout << s << endl;
	
	}
	
	return 0;
}