题目U377740
怎么还不写LaTeX啊
MLEin#7-10
代码如下

#include<bits/stdc++.h>
using namespace std;
#define fup(i,start,stop) for(int i=(start);i<=(stop);i++)
#define fupp(j,start,stop) for(int j=(start);j<=(stop);j++)
#define fdw(i,start,stop) for(int i=(start);i>=(stop);i--)
#define fdww(j,start,stop) for(int j=(start);j>=(stop);j--)
#define ull unsigned long long
#define ll long long
#define faster ios::sync_with_stdio(false)
#define endl '\n'
#define fsin cin.tie(0)
#define fsout cout.tie(0)
#define xsout(ws)cout.precision((ws))
#define interesting int
//#define int long long
//#define int unsigned long long
int main(){
	faster;
	fsin;
	fsout;
	deque <char> c;
	char s;
	ll n;
	int k;
	cin>>k>>n;
	fup(i,1,k){
		c.push_front(char(65+i-1));
	}
	fup(i,1,n){
		s=c.back();
		c.pop_back();
		c.push_front(s);
		c.push_front(s);
	}
	cout<<c.front();
	return 0;
}