diff --git a/src/P2822/P2822.cpp b/src/P2822/P2822.cpp
index 2a2f56a..d452170 100644
--- a/src/P2822/P2822.cpp
+++ b/src/P2822/P2822.cpp
@@ -1,24 +1,29 @@
 #include <iostream>
 #include <algorithm>
+#include <map>
 
 using ull = unsigned long long;
 #define NV(v)#v<<" : "<<(v)
 
-static constexpr ull fact(const ull n)noexcept{
+static ull t, k, n, m, ans;
+static std::map<ull,ull> fact_map;
+
+static ull fact(const ull n)noexcept{
     if(n==0)return 1;
+    const auto it = fact_map.find(n);
+    if(it !=  fact_map.end())return (*it).second;
     ull ret {1};
     for(ull i{2};i<=n;i++){
-        ret*=i;
+        ret=(ret*i)%k;
     }
+    fact_map.insert({n,ret});
     return ret;
 }
 
-static constexpr ull C(const ull n, const ull m)noexcept{
-    return fact(n)/(fact(m)*fact(n-m));
+static ull C(const ull n, const ull m)noexcept{
+    return fact(n)/(fact(m)*fact(n-m)%k);
 }
 
-static ull t, k, n, m, ans;
-
 int main(){
     // std::cout<<NV(fact(0))<<'\n'<<NV(fact(3))<<'\n';
     std::iostream::sync_with_stdio(false), std::cin.tie(nullptr), std::cout.tie(nullptr);