const reader = require("readline").createInterface({
  input: process.stdin, output: process.stdout
});
let lines = [];
reader.on("line", line => { lines.push(line);
});
reader.on("close", () => {
  let num1 = parseInt(lines[0], 10)
  let num2 = parseInt(lines[1], 10)
  let num3 = parseInt(lines[2], 10)
  let ary = [
    {name:"A", value: num1},
    {name:"B", value: num2},
    {name:"C", value: num3},
  ]
  ary.sort(function(a,b){
    if(a.value>b.value) return -1;
    if(a.value < b.value) return 1;
    return 0;
  });
  console.log(ary[0].name)
  console.log(ary[1].name)
  console.log(ary[2].name)
});