#include <bits/stdc++.h>

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = std::int64_t;
using P = std::tuple<int,int>;

int A[3];

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    for(int i=0;i<3;++i){
        std::cin >> A[i];
    }

    char c = 'A' + (std::max_element(A, A + 3) - A);
    std::cout << c << std::endl;
}

