function commonDiv (num1,num2) {
    "use strict";
  if(num1 < num2){
      let tmp = num1;
        num1 = num2;
        num2 = tmp;
  }
  let num3 = num1 % num2;
  if(num3 === 0) {
      return num2;
  } else {
      return commonDiv(num2, num3);
  }

}

function Main(input) {
    "use strict";
    const els = input.split('\n');
    const number = els[0];
    const values = els[1].split(' ');
    let output;
    let results = [];


    for (let i = 0; i < number-1 ; i++) {
        results.push(commonDiv(parseInt(values[i],10), parseInt(values[i+1],10)));
    }
    results.push(commonDiv(parseInt(values[0],10), parseInt(values[number-1],10)));

    let min = Math.min.apply(null, results);
    const newResults = results.filter(n => n != min);

    if(values.length === 2){
        output = commonDiv(parseInt(values[0],10), parseInt(values[1],10));
        console.log(output);
        return;
    }

    if(newResults.length === 0){
        output = parseInt(values[0],10);
        console.log(output);
        return;
    }

    output = Math.min.apply(null,newResults);

    console.log(output);
}

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