const main = (L,R) => {
    var result = Math.pow(10,9)
    
    if(R - L >= 2019) {
        return 0
    }

    if(R*L>2019) {
        for(var i = L;i<R;i++) {
            for(var j = i+1;j<R+1;j++) {
                result = Math.min(result,i*j% 2019)
                if(result === 0) {
                    return result
                }
            }
        }
    
        return result
    }else{
        return L*(L+1)

    }
    

}

const input = require('fs').readFileSync('/dev/stdin','utf8').split("\n")[0]
const LR = input.split(" ").map(i => Number(i))
console.log(main(LR[0],LR[1]))