diff --git a/main.cpp b/main.cpp
index 4af1c62..9de5622 100644
--- a/main.cpp
+++ b/main.cpp
@@ -13,11 +13,12 @@ using namespace std;
     };
 
 Input
-input_data()
+input_data(istream& tin, bool promt)
 {
     size_t n;
+    if (promt)
     cerr<<"Marks: ";
-    cin>>n;
+    tin>>n;
 
     Input in;
     in.A.resize(n);
@@ -27,17 +28,17 @@ input_data()
         cin>>in.A[i];
     }
 
+    if (promt)
     cerr<<"Rows: ";
-    cin>>in.bin;
+    tin>>in.bin;
     return in;
 }
 
 int main()
 {
-    Input in = input_data();
+    auto in = input_data(cin, false);
     auto B = make_histogram(in.A, in.bin);
     show_histogram_svg (B);
-    123;
 
     return 0;
 }