let i = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n')[1].split(' ').map((e) => parseInt(e)).sort((a,b) => a-b)
let m = 1000001
i.reduce((p,c) => {
  let d = Math.abs(p-c)
  if (d !=0 && d < m) m = d
  return c
})
if (m == 1000001) m = 0
console.log(m)