function compare(a,b){
  return a-b;
}

function Main(input){
  var d=input.split("\n");
  var x=d[1].split(" ");
  var ary=[];
  for(var i=0; i<x.length; ++i){
    ary.push(x[i]);
  }
  ary.sort(compare);
  var y=1e6;
  for(var i=0; i<ary.length-1; ++i){
    var a=ary[i];
    var b=ary[i+1];
    if(a!=b){
      var c=b-a;
      if(c<y) y=c;
    }
  }
  if(y==1e6) y=0;
  console.log(y);
}

Main(require("fs").readFileSync("/dev/stdin","utf-8"));