From c5feea8355a86d2ffd86a43854cf289b951547cb Mon Sep 17 00:00:00 2001
From: Nirali Sahoo <58680652+nizz009@users.noreply.github.com>
Date: Fri, 23 Oct 2020 12:27:17 +0530
Subject: [PATCH 1/2] Uploaded program-21

Addition of Program-21 in C++ directory which aims to find the last digit of partial Fibonacci Series.
---
 C++/Program-21/README.md   | 26 ++++++++++++++++++++++++++
 C++/Program-21/program.cpp | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 C++/Program-21/README.md
 create mode 100644 C++/Program-21/program.cpp

diff --git a/C++/Program-21/README.md b/C++/Program-21/README.md
new file mode 100644
index 00000000..82aa3347
--- /dev/null
+++ b/C++/Program-21/README.md
@@ -0,0 +1,26 @@
+#Last digit of sum of partial Fibonacci Series
+
+##Problem statement:
+Given two non-negative integers m and n, where m <= n, find the last digit of the sum *Fm + Fm+1 + .... + Fn*
+
+###Input:
+Two non negative intergers m and n, such that m <= n.
+
+###Output: 
+The last digit of the sum of Fibonacci series starting from *Fm* to *Fn*.
+
+###Example:
+
+*Input:*
+```
+3 7
+```
+*Output:*
+```
+1
+```
+*Explanation:*
+```
+𝐹3 + 𝐹4 + 𝐹5 + 𝐹6 + 𝐹7 = 2 + 3 + 5 + 8 + 13 = 31
+Last digit of 31 = 1
+```
diff --git a/C++/Program-21/program.cpp b/C++/Program-21/program.cpp
new file mode 100644
index 00000000..52bd1d2d
--- /dev/null
+++ b/C++/Program-21/program.cpp
@@ -0,0 +1,37 @@
+/* Compute the last digit of the sum of partial Fibonacci series. (Given two non-negative integers m and n, where m <= n, find the last digit of the sum Fm + Fm+1 + .... + Fn) */
+
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long int ll;
+
+void solve()
+{
+   ll n = 0, m = 0;
+   int b[60] = {0, 1, 2, 4, 7, 2, 0, 3, 4, 8, 3, 2, 6, 9, 6, 6, 3, 0, 4, 5, 0, 6, 7, 4, 2, 7, 0, 8, 9, 8, 8, 7, 6, 4, 1, 6, 8, 5, 4, 0, 5, 6, 2, 9, 2, 2, 5, 8, 4, 3, 8, 2, 1, 4, 6, 1, 8, 0, 9, 0};
+   int i = 0, j = 0, sum = 0;
+
+   cin >> n >> m;
+
+   i = (n-1) % 60;
+   j = m % 60;
+
+   if(b[j] >= b[i])
+   {
+      cout << b[j] - b[i] << "\n";
+   }
+   else
+   {
+      b[j] += 10;
+      cout << b[j] - b[i] << "\n";
+   }
+}
+
+int main()
+{
+   //for fast input output
+   ios_base::sync_with_stdio(false);cin.tie(NULL);
+
+   solve();
+ 
+   return 0;
+}
\ No newline at end of file

From cd0fb12c9a2a9ec74ff184e9bd7839fecca36fc2 Mon Sep 17 00:00:00 2001
From: Nirali Sahoo <58680652+nizz009@users.noreply.github.com>
Date: Fri, 23 Oct 2020 12:28:02 +0530
Subject: [PATCH 2/2] Update README.md

---
 C++/Program-21/README.md | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/C++/Program-21/README.md b/C++/Program-21/README.md
index 82aa3347..2b4cfbeb 100644
--- a/C++/Program-21/README.md
+++ b/C++/Program-21/README.md
@@ -1,15 +1,15 @@
-#Last digit of sum of partial Fibonacci Series
+# Last digit of sum of partial Fibonacci Series
 
-##Problem statement:
+## Problem statement:
 Given two non-negative integers m and n, where m <= n, find the last digit of the sum *Fm + Fm+1 + .... + Fn*
 
-###Input:
+### Input:
 Two non negative intergers m and n, such that m <= n.
 
-###Output: 
+### Output: 
 The last digit of the sum of Fibonacci series starting from *Fm* to *Fn*.
 
-###Example:
+### Example:
 
 *Input:*
 ```