Go: package main

import "fmt"

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max3(a, b, c int) int {
	return max(max(a, b), c)
}

func main() {
	var (
		a, b, c int
		ch      byte
	)
	fmt.Scanln(&a, &b, &c)
	m := max3(a, b, c)
	switch m {
	case a:
		ch = 'A'
	case b:
		ch = 'B'
	case c:
		ch = 'C'
	}
	fmt.Printf("%c\n", ch)
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream>
#include <random>
#include <map>
#include <fstream>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <assert.h>
#include <complex>
using namespace std;
#define eps 0.000001
#define LONG_INF 10000000000000
#define GOLD 1.61803398874989484820458
#define MAX_MOD 1000000007
#define MOD 998244353
#define seg_size 65536*4
#define REP(i,n) for(long long i = 0;i < n;++i)
int main() {
	vector<pair<int, char>> input;
	REP(i, 3) {
		long long geko;
		cin >> geko;
		input.push_back(make_pair(geko, 'A' + i));
	}
	sort(input.begin(), input.end());
	cout << input[2].second << endl;
	return 0;
}

C++: #include <cassert>

#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
//#include <boost/foreach.hpp>
//#include <boost/range/algorithm.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
#define INF 1e9
#define LINF 1e18
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define MOD 1000000007LL
#define int long long
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
struct edge{int to,cost;};
//typedef pair<int,int> P;

bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool isPrime(int x){if(x==1)return 0;if(x==2)return 1;if(x%2==0)return 0;for(int i=3;i*i<=x;i++)if(x%i==0)return 0;return 1;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}
bool isnumber(char c){return ('0'<=c&&c<='9');}
bool isalpha(char c){return (isupper(c)||islower(c));}
void printvi(vector<int> v){rep(i,0,v.size()){if(i)cout<<" ";cout<<v[i];}cout<<endl;}
void printvil(vector<int> v){rep(i,0,v.size()){cout<<v[i]<<endl;}}
void printvvi(vector<vector<int>> v){
    rep(i,0,v.size()){
        rep(j,0,v[i].size()){
            if(j)cout<<" ";
            cout<<v[i][j];
        }
        cout<<endl;
    }
}
void printvstr(vector<string> v){
    rep(i,0,v.size()){
        cout<<v[i]<<endl;
    }
}

int gcd(int a,int b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    else return gcd(b,a%b);
}

struct S{
    int id,team,ac,pena;
};

string alllower(string s){
    string ret;
    rep(i,0,s.size()){
        if(isupper(s[i]))ret+=char(s[i]+'a'-'A');
        else ret+=s[i];
    }
    return ret;
}

string first_upper(string s){
    string ret;
    rep(i,0,s.size()){
        if(i==0 && islower(s[i]))ret+=char(s[i]-('a'-'A'));
        else ret+=s[i];
    }
    return ret;
}

signed main (){
    int a,b,c;
    cin>>a>>b>>c;
    if(a>c and a>b)cout<<"A"<<endl;
    else if(b>a and b>c)cout<<"B"<<endl;
    else cout<<"C"<<endl;



    
}
/*
*/

C++: #include <bits/stdc++.h>

using namespace std;
typedef long long ll;

// #define DEBUG




int main()
{
#ifdef DEBUG
    cout << "DEBUG MODE" << endl;
    ifstream in("input.txt"); //for debug
    cin.rdbuf(in.rdbuf());    //for debug
#endif

    int a, b, c;
    string ans;
    cin >> a >> b >> c;
    int d[3] = {a, b, c};
    sort(d, d+3);

    if (a == d[2]) ans = "A";
    else if (b == d[2]) ans = "B";
    else if (c == d[2]) ans = "C";
    cout << ans << endl;
    return 0;
}

C++: //↓template↓

#include "bits/stdc++.h"
using namespace std;
#define Would
#define you
#define all(n)  n.begin(),n.end()
const long long INF = 1e18;
const long long MOD = 1e9 + 7;
const double pi = acos(-1);
const int SIZE = 1 << 17;
int dx[] = { 1,0 }, dy[] = { 0,1 }, alp[30];
long long fac[200005], finv[200005], inv[200005];
vector<long long>dij;
struct edge { long long to, cost; };
vector<vector<edge> >G;

long long mod_pow(long long a, long long b) {
	long long res = 1, mul = a;
	for (int i = 0; i < 31; ++i) {
		if (b >> i & 1) {
			res *= mul;
			res %= MOD;
		}
		mul = (mul * mul) % MOD;
	}

	return res;
}

void addedge(int from, int to, int cost) {
	G[from].push_back({ to,cost });
	G[to].push_back({ from,cost });
}

//↑template↑

char out = 'C';
int main() {
	int a, b, c;
	cin >> a >> b >> c;
	int ans = min({ a,b,c });

	if (ans == a) { out = 'A'; }
	else if (ans = b) { out = 'B'; }

	cout << out << endl;
}

C++: #include<bits/stdc++.h>

using namespace std;

typedef struct n
{
    int z;
    char c;
}c;

bool com(c a,c b){

    if(a.z>=b.z)return true;
    else return false;

}
int main()
{
    c ar[3];
    cin>>ar[0].z>>ar[1].z>>ar[2].z;
    ar[0].c='A';
    ar[1].c='B';
    ar[2].c='C';
    sort(ar,ar+3,com);
    cout<<ar[0].c<<endl;
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    int maxi = max(a, max(b, c));
    if(maxi == a) cout << "A" << endl;
    if(maxi == b) cout << "B" << endl;
    if(maxi == c) cout << "C" << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
typedef long long int ll;

#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
#define MOD (1000000007)
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1}; // 移動方向

pair<int, char> a,b,c;

void input(){
    int x, y, z;
    cin >> x >> y >> z;
    a.first = x;
    b.first = y;
    c.first = z;
    a.second = 'A';
    b.second = 'B';
    c.second = 'C';
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    input();
    vector<pair<int, char>> abc = {a, b, c};
    std::sort(abc.begin(), abc.end(), [](const auto& a, const auto& b){return a.first > b.first;});
    cout << abc[0].second << endl;
    return 0;
}