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

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