var readline = require('readline');
var rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  terminal: false
});

rl.on('line', function(line){
     if (line ==line.toUpperCase()) {
     console.log('A');
    }
    if (line == line.toLowerCase()){
    console.log('a');
    }
})