Go: package main

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

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	a := getNextInt(scanner)
	b := getNextInt(scanner)
	c := getNextInt(scanner)
	if a == most(a, b, c) {
		fmt.Fprintln(writer, "A")
		return
	}
	if b == most(a, b, c) {
		fmt.Fprintln(writer, "B")
		return
	}
	fmt.Fprintln(writer, "C")
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}
func most(a, b, c int) int {
	return max(a, max(b, c))
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-2;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;


int main() {
	int a, b, c; cin >> a >> b >> c;
	if (a > b&&a > c)cout << "A" << endl;
	else if (b > a&&b > c)cout << "B" << endl;
	else cout << "C" << endl;
	//stop
	return 0;
}

C++: #include<iostream>
using namespace std;
signed main() {
	int a, b, c; cin >> a >> b >> c;
	if (a > b&&a > c)cout << "A\n";
	else cout << (b > c ? "B\n" : "C\n");
}

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

int a, b, c, ans;

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

  return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<vector>
#include<algorithm>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<math.h>
#include<functional>
#include<bitset>
using namespace std;
using ll = long long;
using ld = long double;
using pint = pair<int, int>;
using pll = pair<ll, ll>;
#define MOD 1000000007LL
#define INF 1000000000LL
#define EPS 1e-10
#define FOR(i,n,m) for(ll i=n;i<(int)m;i++)
#define REP(i,n) FOR(i,0,n)
#define DUMP(a) REP(d,a.size()){cout<<a[d];if(d!=a.size()-1)cout<<" ";else cout<<endl;}
#define ALL(v) v.begin(),v.end()
#define UNIQUE(v)  sort(ALL(v));v.erase(unique(ALL(v)),v.end());
#define pb push_back

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int a, b, c;
	cin >> a >> b >> c;
	if(a > max(b, c)) cout << 'A' << endl;
	if(b > max(c, a)) cout << 'B' << endl;
	if(c > max(a, b)) cout << 'C' << endl;
}
/* --------------------------------------- */

C++: #include<bits/stdc++.h>
#define INF 1e9
#define llINF 1e18
#define MOD 1000000007
#define pb push_back
#define mp make_pair 
#define F first
#define S second
#define ll long long
#define ull unsigned long long
#define vi vector<ll>
#define vvi vector<vi>
#define BITLE(n) (1LL<<(n))
#define BITCNT(n) (__builtin_popcountll(n))
#define SUBS(s,f,t) ((s).substr((f)-1,(t)-(f)+1))
#define ALL(a) (a).begin(),(a).end()
using namespace std;
struct Grid{ll x,y,t;};
struct Edge{ll to,cost;};
struct Graph{vector<vector<Edge>>E;int V;
  const ll Inf = llINF;const int MAX_V=201010;vector<ll>d;
  Graph(int n):E(n){d.resize(MAX_V);E.resize(n);V=n;}
  void init(){for(int i=0;i<MAX_V;i++)d[i]=Inf;}
  void add_edge(ll from,ll to,ll cost){E[from].pb({to,cost});}
};
int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll a,b,c;cin>>a>>b>>c;
  if(a>=b&&a>=c)cout<<"A"<<endl;
  else if(b>=a&&b>=c)cout<<"B"<<endl;
  else cout<<"C"<<endl;
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
typedef pair<int,P> P1;
typedef pair<P,P> P2;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define mod 998244353
#define fi first
#define sc second
#define rep(i,x) for(int i=0;i<x;i++)
#define repn(i,x) for(int i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())

int a,b,c;

int main(){
	cin>>a>>b>>c;
	int d = max(a,max(b,c));
	if(a == d) puts("A");
	if(b == d) puts("B");
	if(c == d) puts("C");
}

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;

template <typename T>
using vec1 = vector<T>;

template <typename T>
T cin2var()
{
    T val;
    cin >> val;
    return val;
}

template <typename T>
vec1<T> cin2vec(size_t size)
{
    vec1<T> vec1;
    for (size_t i = 0; i < size; ++i) {
        vec1.push_back(cin2var<T>());
    }
    return vec1;
}

void sub()
{
    constexpr size_t N = 3;
    const auto lunchs(cin2vec<size_t>(N));
    const auto iteMax(max_element(lunchs.cbegin(), lunchs.cend()));
    const char no = iteMax - lunchs.cbegin();
    cout << static_cast<char>('A' + no) << endl;
}

int main()
{
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    sub();
    return 0;
}