diff --git a/lab1.cpp b/lab1.cpp
index 8e3e6ea..113e5d9 100644
--- a/lab1.cpp
+++ b/lab1.cpp
@@ -10,15 +10,15 @@ struct Input {
     size_t bin_count{};
 };
 
-Input input_data() {
+Input input_data(istream& in_stream) {
     Input in;
     size_t number_count;
-    cin >> number_count;
+    in_stream >> number_count;
     in.numbers.resize(number_count);
     for (size_t i = 0; i < number_count; i++) {
-        cin >> in.numbers[i];
+        in_stream >> in.numbers[i];
     }
-    cin >> in.bin_count;
+    in_stream >> in.bin_count;
     return in;
 }
 
@@ -26,7 +26,7 @@ int main()
 {
     const size_t SCREEN_WIDTH = 80;
     const size_t MAX_ASTERISK = SCREEN_WIDTH - 3 - 1;
-    auto in = input_data();
+    auto in = input_data(cin);
     vector<double> numbers_data = in.numbers;
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins, in.numbers, in.bin_count);
diff --git a/unittest.cpp b/unittest.cpp
index de25e8b..67a1d6e 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -15,8 +15,7 @@ TEST_CASE("distinct positive numbers") {
 TEST_CASE("empty vector") {
     double min = 0;
     double max = 0;
-    bool flag;
-    flag = find_minmax({}, min, max);
+    CHECK(!find_minmax({}, min, max));
 }
 
 TEST_CASE("negative values") {