diff --git a/histogram.cpp b/histogram.cpp
new file mode 100644
index 0000000..0bf4fff
--- /dev/null
+++ b/histogram.cpp
@@ -0,0 +1,48 @@
+#include "histogram.h"
+
+using namespace std;
+
+static void
+find_minmax(const std::vector<double>& numbers, double& Min, double& Max) {
+    Min = numbers[0];
+    Max = numbers[0];
+    for(size_t x : numbers)
+    {
+        if(x < Min)
+        {
+            Min = x;
+        }else
+        {
+            if(x > Max)
+            {
+                Max = x;
+            }
+        }
+    }
+}
+std::vector<size_t> make_histogram(std::vector<double> numbers, size_t bin_count)
+{
+    std::vector<size_t> bins(bin_count);
+    double Min, Max;
+    find_minmax(numbers, Min, Max);
+    double bin_size = (Max - Min) / bin_count;
+    for (double x : numbers)
+        {
+            bool found = false;
+            for (size_t j = 0; (j < bin_count - 1) && !found; j++)
+            {
+                auto lo = Min + j * bin_size;
+                auto hi = Min + (j + 1) * bin_size;
+                if ((lo <= x) && (x < hi))
+                {
+                    bins[j]++;
+                    found = true;
+                }
+            }
+            if (!found)
+            {
+                bins[bin_count - 1]++;
+            }
+        }
+    return bins;
+}
diff --git a/histogram.h b/histogram.h
new file mode 100644
index 0000000..aab82b8
--- /dev/null
+++ b/histogram.h
@@ -0,0 +1,9 @@
+#ifndef HISTOGRAM_H_INCLUDED
+#define HISTOGRAM_H_INCLUDED
+#include <iostream>
+#include <vector>
+
+std::vector<size_t>
+make_histogram(const std::vector<double> numbers, size_t bin_count);
+
+#endif // HISTOGRAM_H_INCLUDED
diff --git a/main.cpp b/main.cpp
index add06c3..1d5c197 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,13 +1,12 @@
 #include <iostream>
 #include <vector>
-
-const size_t SCREEN_WIDTH = 80;
-const size_t MAX_ASTERISK = SCREEN_WIDTH - 3 - 1;
-
+#include "text.h"
+#include "histogram.h"
 using namespace std;
 struct Input {
-    vector<double> numbers;
+    std::vector<double> numbers;
     size_t bin_count{};
+    size_t number_count{};
 };
 Input
 input_data() {
@@ -22,72 +21,6 @@ input_data() {
     cin >> in.bin_count;
     return in;
 }
-void find_minmax(const vector<double>& numbers, double& Min, double& Max) {
-    Min = numbers[0];
-    Max = numbers[0];
-    for(size_t x : numbers)
-    {
-        if(x < Min)
-        {
-            Min = x;
-        }else
-        {
-            if(x > Max)
-            {
-                Max = x;
-            }
-        }
-    }
-}
-vector<size_t>
-make_histogram(vector<double> numbers, size_t bin_count)
-{
-    std::vector<size_t> bins(bin_count);
-    double Min, Max;
-    find_minmax(numbers, Min, Max);
-    double bin_size = (Max - Min) / bin_count;
-    for (double x : numbers)
-        {
-            bool found = false;
-            for (size_t j = 0; (j < bin_count - 1) && !found; j++)
-            {
-                auto lo = Min + j * bin_size;
-                auto hi = Min + (j + 1) * bin_size;
-                if ((lo <= x) && (x < hi))
-                {
-                    bins[j]++;
-                    found = true;
-                }
-            }
-            if (!found)
-            {
-                bins[bin_count - 1]++;
-            }
-        }
-        return bins;
-}
-void show_histogram_text(vector<size_t> bins, size_t bin_count)
-{
-    size_t max_count = bins[0];
-    for(size_t x : bins)
-    {
-        if(x > max_count)
-        {
-            max_count = x;
-        }
-    }
-    for(size_t i = 0;i<bin_count;i++){
-    size_t height = bins[i];
-    printf("%3d:", bins[i]);
-    if(max_count > MAX_ASTERISK)
-    height = MAX_ASTERISK * (static_cast<double>(bins[i]) / max_count);
-    for(size_t j = 0;j<height;j++)
-    {
-        cout<<"*";
-    }
-    cout<<endl;
-    }
-}
 int main()
 {
     auto in = input_data();
diff --git a/text.cpp b/text.cpp
new file mode 100644
index 0000000..3ce093a
--- /dev/null
+++ b/text.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+#include <vector>
+#include "text.h"
+using namespace std;
+
+const size_t SCREEN_WIDTH = 80;
+const size_t MAX_ASTERISK = SCREEN_WIDTH - 3 - 1;
+
+void show_histogram_text(const std::vector<size_t> bins, size_t bin_count)
+{
+    size_t max_count = bins[0];
+    for(size_t x : bins)
+    {
+        if(x > max_count)
+        {
+            max_count = x;
+        }
+    }
+    for(size_t i = 0;i<bin_count;i++){
+    size_t height = bins[i];
+    printf("%3d:", bins[i]);
+    if(max_count > MAX_ASTERISK)
+    height = MAX_ASTERISK * (static_cast<double>(bins[i]) / max_count);
+    for(size_t j = 0;j<height;j++)
+    {
+        cout<<"*";
+    }
+    cout<<endl;
+    }
+}
diff --git a/text.h b/text.h
new file mode 100644
index 0000000..c7f792a
--- /dev/null
+++ b/text.h
@@ -0,0 +1,10 @@
+#ifndef TEXT_H_INCLUDED
+#define TEXT_H_INCLUDED
+
+#include <vector>
+#include <iostream>
+
+void
+show_histogram_text(const std::vector<size_t> bins, size_t bin_count);
+
+#endif // TEXT_H_INCLUDED