'use strict';
function main(input) {
  const args = input.split(' '),
        L = parseInt(args[0]),
        R = parseInt(args[1]);
  let min = 2019;
  if (R-L > 2018) {
    min = 0;
  } else {
    for (let i = L; i <= R-1; ++i) {
      for (let j = i+1; j <= R; ++j) {
        let tmp = (i*j) % 2019;
        if (tmp < min) {
          min = tmp;
        }
      }
    }
  }
  console.log(min);
}

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