diff --git a/main.cpp b/main.cpp
index c8a6784..08c7870 100644
--- a/main.cpp
+++ b/main.cpp
@@ -11,22 +11,22 @@ struct Input {
 };
 
 Input
-input_data() {
+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 in1;
+    in1.numbers.resize(number_count);
     cerr << "Enter numbers: ";
     for (size_t i = 0; i < number_count; i++) {
-        cin >> in.numbers[i];
+        in >> in1.numbers[i];
     }
 
     cerr << "Enter bin count: ";
-    cin >> in.bin_count;
+    in >> in1.bin_count;
 
-    return in;
+    return in1;
 }
 
 int main()
@@ -34,7 +34,7 @@ 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);
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins);
     return 0;