
function main(arg) {
  const input = arg.split('\n');
  const ary = input[1].split(' ');
　
while(input[0] > 1){  
  var tmp1 = 10000;
  var num1 = 0;
  for(var i = 0; i < input[0]; i++){
    if(tmp1 > Number(ary[i])){
      tmp1 = Number(ary[i]);
      num1 = i;
    }
  }
  ary.splice(num1,1);
  // console.log(ary);
  
  var tmp2 = 999;
  var num2 = 0;
  for(var i = 0; i < input[0]; i++){
    if(tmp2 > Number(ary[i])){
      tmp2 = Number(ary[i]);
      num2 = i;
    }
  }
  ary.splice(num2,1);
  
  tmp3 = (tmp1+tmp2)/2;
  ary.push(`${tmp3}`);
  input[0] -= 1;
  // console.log(ary);
}
  console.log(ary[0]);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));