diff --git a/main.cpp b/main.cpp
index c6d217e..5f70b72 100644
--- a/main.cpp
+++ b/main.cpp
@@ -11,19 +11,22 @@ struct Input {
     size_t bin_count{};
 };
 Input
-input_data(){
+input_data(istream& in){
     size_t number_count;
-	cin >> number_count;
-	Input in;
-	in.numbers.resize(number_count);
+    cerr << "Enter number count: ";
+	in >> number_count;
+	Input input;
+	input.numbers.resize(number_count);
+	cerr << "Enter numbers: ";
 	for (size_t i = 0; i < number_count; i++){
-		cin >> in.numbers[i];
+		in >> input.numbers[i];
 	}
-	cin >> in.bin_count;
-	return in;
+	cerr << "Enter bin count: ";
+	in >> input.bin_count;
+	return input;
 }
 int main(){
-	auto in = input_data();
+	auto in = input_data(cin);
 	auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins);
 }