var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  var antena=[];
  for(var i=0;i<lines.length;i++){
    antena.push(Number(lines[i]));
  } 
  if(antena[antena.length-1]<Math.max.apply(null, antena)-Math.min.apply(null,antena)){
  	console.log(":(");
  }else{
  	console.log("Yay!");
  }
});