Update README.md

Author: Lokesh598

README.md

@@ -84,6 +84,9 @@
 200 medium problems solved 27th march 2024. now target for next 100 medium problems.
 
 ![image](https://github.com/Lokesh598/data-structures-and-algorithm/assets/63910828/42eaa8db-81cf-462b-89ad-44aae4839b44)
+![image](https://github.com/Lokesh598/data-structures-and-algorithm/assets/63910828/c51e1398-9346-4636-aa2e-be39f7136c9d)
+400 problems solved
+
 
 
 ![image](https://github.com/Lokesh598/data-structures-and-algorithm/assets/63910828/6ee91c8b-5390-483c-b52d-013d2ac50d12)