diff --git a/2020/day05/main.go b/2020/day05/main.go
new file mode 100644
index 0000000..306d92c
--- /dev/null
+++ b/2020/day05/main.go
@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strings"
+)
+
+func parseInput(file string) []string {
+	content, err := os.ReadFile(file)
+	if err != nil {
+		log.Fatalf("Failed to read input file: %v", err)
+	}
+	return strings.Split(string(content), "\n")
+}
+
+func PartOne(input []string) int {
+	maxSeatID := 0
+	for _, pass := range input {
+		rowStr := pass[:7]
+		columnStr := pass[7:10]
+
+		row := 0
+		for idx, char := range rowStr {
+			if char == 'B' {
+				row |= 1 << (6 - idx)
+			}
+		}
+
+		column := 0
+		for idx, char := range columnStr {
+			if char == 'R' {
+				column |= 1 << (2 - idx)
+			}
+		}
+
+		seatID := row*8 + column
+		if seatID > maxSeatID {
+			maxSeatID = seatID
+		}
+	}
+	return maxSeatID
+}
+
+func main() {
+	input := parseInput("input.txt")
+	fmt.Println("Part 1:", PartOne(input))
+}