diff --git a/main.cpp b/main.cpp
index 9705337..ab81cdc 100644
--- a/main.cpp
+++ b/main.cpp
@@ -11,7 +11,7 @@ struct Input {
     size_t max_count{};
 };
 Input
-input_data() {
+input_data(istream& cin) {
     Input in;
     cerr << "Enter number count: ";
     cin >> in.number_count;
@@ -30,7 +30,7 @@ input_data() {
 }
 int main()
 {
-    auto in = input_data();
+    auto in = input_data(cin);
     auto bins = make_histogram(in.numbers, in.bin_count, in.number_count, in.max_count);
     show_histogram_svg(bins, in.max_count, in.bin_count);
     return 0;