diff --git a/hw10_program_optimization/go.mod b/hw10_program_optimization/go.mod
index d0736cd..81dbf2a 100644
--- a/hw10_program_optimization/go.mod
+++ b/hw10_program_optimization/go.mod
@@ -2,4 +2,7 @@ module github.com/tiburon-777/HW_OTUS/hw10_program_optimization
 
 go 1.14
 
-require github.com/stretchr/testify v1.5.1
+require (
+	github.com/json-iterator/go v1.1.10
+	github.com/stretchr/testify v1.5.1
+)
diff --git a/hw10_program_optimization/go.sum b/hw10_program_optimization/go.sum
index 331fa69..c1291ea 100644
--- a/hw10_program_optimization/go.sum
+++ b/hw10_program_optimization/go.sum
@@ -1,8 +1,18 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/json-iterator/go v1.1.10 h1:Kz6Cvnvv2wGdaG/V8yMvfkmNiXq9Ya2KUv4rouJJr68=
+github.com/json-iterator/go v1.1.10/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OHLH3mGKHDcjJRFFRrJa6eAM5H+CtDdOsPc=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 h1:Esafd1046DLDQ0W1YjYsBW+p8U2u7vzgW2SQVmlNazg=
+github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
diff --git a/hw10_program_optimization/stats.go b/hw10_program_optimization/stats.go
index 5cee6f1..f4111fc 100644
--- a/hw10_program_optimization/stats.go
+++ b/hw10_program_optimization/stats.go
@@ -1,11 +1,11 @@
 package hw10_program_optimization //nolint:golint,stylecheck
 
 import (
-	"encoding/json"
-	"fmt"
+	"bufio"
 	"io"
-	"io/ioutil"
 	"strings"
+
+	jsoniter "github.com/json-iterator/go"
 )
 
 type User struct {
@@ -20,42 +20,24 @@ type User struct {
 
 type DomainStat map[string]int
 
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+
 func GetDomainStat(r io.Reader, domain string) (DomainStat, error) {
-	u, err := getUsers(r)
-	if err != nil {
-		return nil, fmt.Errorf("get users error: %s", err)
-	}
-	return countDomains(u, domain)
-}
-
-type Users []User
-
-func getUsers(r io.Reader) (Users, error) {
-	result := make([]User, 10000)
-	content, err := ioutil.ReadAll(r)
-	if err != nil {
-		return result, err
-	}
-
-	lines := strings.Split(string(content), "\n")
-	for _, line := range lines {
-		var user User
-		if err = json.Unmarshal([]byte(line), &user); err != nil {
-			return result, err
+	result := make(DomainStat)
+	var err error
+	var user User
+	e := bufio.NewReader(r)
+	for {
+		line, _, err := e.ReadLine()
+		if err == io.EOF {
+			break
+		}
+		if err = json.Unmarshal(line, &user); err != nil {
+			return nil, err
+		}
+		if strings.Contains(user.Email, "."+domain) {
+			result[strings.ToLower(strings.SplitN(user.Email, "@", 2)[1])]++
 		}
-		result = append(result,user)
 	}
 	return result, err
 }
-
-func countDomains(u Users, domain string) (DomainStat, error) {
-	result := make(DomainStat)
-	i:=0
-	for _, user := range u {
-		if strings.Contains(user.Email,"."+domain) {
-			result[strings.ToLower(strings.SplitN(user.Email, "@", 2)[1])]++
-			i++
-		}
-	}
-	return result, nil
-}