No problem, we've got 1399 and 1239 to multiply
1399 × 1239 = 1239 × (1399)
+ 1239 × 9 that results in 11151
+ 1239 × 90 giving us 111510
+ 1239 × 300 giving us 371700
+ 1239 × 1000 producing 1239000

= 1733361
