diff --git a/2015/day16/main.go b/2015/day16/main.go
new file mode 100644
index 0000000..f15d81e
--- /dev/null
+++ b/2015/day16/main.go
@@ -0,0 +1,99 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+
+	"github.com/alexchao26/advent-of-code-go/util"
+)
+
+func main() {
+	var part int
+	flag.IntVar(&part, "part", 1, "part 1 or 2")
+	flag.Parse()
+	fmt.Println("Running part", part)
+
+	ans := auntSue(util.ReadFile("./input.txt"), part)
+	fmt.Println("Output:", ans)
+}
+
+var targetSue = map[string]int{
+	"children":    3,
+	"cats":        7,
+	"samoyeds":    2,
+	"pomeranians": 3,
+	"akitas":      0,
+	"vizslas":     0,
+	"goldfish":    5,
+	"trees":       3,
+	"cars":        2,
+	"perfumes":    1,
+}
+
+func auntSue(input string, part int) int {
+	for _, line := range strings.Split(input, "\n") {
+		var thing1, thing2, thing3 string
+		var sueNum, amount1, amount2, amount3 int
+		// Sue 1: goldfish: 6, trees: 9, akitas: 0
+		_, err := fmt.Sscanf(line, "Sue %d: %s %d, %s %d, %s %d",
+			&sueNum, &thing1, &amount1, &thing2, &amount2, &thing3, &amount3)
+		if err != nil {
+			panic(err)
+		}
+		thing1 = strings.Trim(thing1, ":")
+		thing2 = strings.Trim(thing2, ":")
+		thing3 = strings.Trim(thing3, ":")
+
+		// put it in a map for part 2 to make it easy to look up a particular
+		// thing's count
+		readingsMap := map[string]int{}
+		readingsMap[thing1] = amount1
+		readingsMap[thing2] = amount2
+		readingsMap[thing3] = amount3
+
+		if part == 1 {
+			allMatch := true
+			for thing, amount := range readingsMap {
+				if targetSue[thing] != amount {
+					allMatch = false
+				}
+			}
+			if allMatch {
+				return sueNum
+			}
+		} else {
+			allRulesMatched := true
+			// check ranges where the scanned number is LESS than target's
+			for _, check := range []string{"cats", "trees"} {
+				if scanCount, found := readingsMap[check]; found {
+					if scanCount <= targetSue[check] {
+						allRulesMatched = false
+					}
+					delete(readingsMap, check)
+				}
+			}
+			// check ranges where chaned number is MORE than target's
+			for _, check := range []string{"pomeranians", "goldfish"} {
+				if scanCount, found := readingsMap[check]; found {
+					if scanCount >= targetSue[check] {
+						allRulesMatched = false
+					}
+					delete(readingsMap, check)
+				}
+			}
+
+			// check literal amounts
+			for thing, amount := range readingsMap {
+				if targetSue[thing] != amount {
+					allRulesMatched = false
+				}
+			}
+			if allRulesMatched {
+				return sueNum
+			}
+		}
+	}
+
+	panic("expect return from loop")
+}
diff --git a/2015/day16/main_test.go b/2015/day16/main_test.go
new file mode 100644
index 0000000..5bb4fbe
--- /dev/null
+++ b/2015/day16/main_test.go
@@ -0,0 +1,26 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/alexchao26/advent-of-code-go/util"
+)
+
+func Test_auntSue(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		part  int
+		want  int
+	}{
+		{"part1 actual", util.ReadFile("input.txt"), 1, 103},
+		{"part2 actual", util.ReadFile("input.txt"), 2, 405},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := auntSue(tt.input, tt.part); got != tt.want {
+				t.Errorf("auntSue() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}