diff --git a/2021/seven.nim b/2021/seven.nim
index dce1e78..2763ff5 100644
--- a/2021/seven.nim
+++ b/2021/seven.nim
@@ -1,6 +1,9 @@
 import std/[strutils, sequtils, tables, strformat]
 import ./common
 
+proc f(n: int): int = toSeq(0..abs(n)).foldl(a + b, 0)
+
+
 proc crabsDistance(input: string): int =
   result = int.high()
   var max_try = 0
@@ -11,10 +14,22 @@ proc crabsDistance(input: string): int =
     let fuel = dists.foldl(a + abs(b - t), 0)
     if fuel < result: result = fuel
 
+proc crabsBigDistance(input: string): int =
+  result = int.high()
+  var max_try = 0
+  let dists = input.split(',').map(parseInt)
+  for d in dists:
+    if d > max_try: max_try = d
+  for t in 0..max_try:
+    let fuel = dists.foldl(a + f(b - t), 0)
+    if fuel < result: result = fuel
+
 let input = 7.loadInputText()
 time("day 7 part 1"): echo input.crabsDistance()
+time("day 7 part 2"): echo input.crabsBigDistance()
 # time("day 7 part 2"): echo "?"
 
 when not defined(release):
   let testInput = "16,1,2,0,4,2,7,1,2,14"
   doAssert testInput.crabsDistance() == 37
+  doAssert testInput.crabsBigDistance() == 168