#!/usr/bin/env tclsh set nums [split [read stdin] \n] set n [llength $nums] for {set i 0} {$i < $n - 2} {incr i} { for {set j [expr {$i+1}]} {$j < $n - 1} {incr j} { for {set k [expr {$j+1}]} {$k < $n} {incr k} { set a [lindex $nums $i] if {$a eq ""} continue set b [lindex $nums $j] if {$b eq ""} continue set c [lindex $nums $k] if {$c eq ""} continue if {$a + $b + $c == 2020} {puts "$a $b $c [expr {$a * $b * $c}]"; exit} } } }