diff --git a/main.cpp b/main.cpp
index a083677..5416286 100644
--- a/main.cpp
+++ b/main.cpp
@@ -10,26 +10,26 @@ struct Input {
     size_t bin_count{};
 };
 
-Input input_data() {
+Input input_data(istream& in) {
     size_t number_count;
     cerr << "Enter number count: ";
-    cin >> number_count;
+    in >> number_count;
 
-    Input in;
-    in.numbers.resize(number_count);
+    Input in_data;
+    in_data.numbers.resize(number_count);
 
     for (size_t i = 0; i < number_count; i++) {
-        cin >> in.numbers[i];
+        in >> in_data.numbers[i];
     }
 
     cerr << "Enter bin count: ";
-    cin >> in.bin_count;
+    in >> in_data.bin_count;
 
-    return in;
+    return in_data;
 }
 
 int main() {
-    auto in = input_data();
+    auto in = input_data(cin);
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins);
 }