'use strict';

function Main(input){
  var line = input.split("\n");
  line.pop();
  line.shift();
  line.sort((a,b)=>{
    if ( a > b ) return -1;
    if ( a < b ) return 1;
    return 0;
  });
  console.log(parseInt(line[0].split(" ")[0],10) + parseInt(line[0].split(" ")[1],10));
}

Main(require('fs').readFileSync('/dev/stdin', 'utf8'));