diff --git a/8.16/S-TrailingZeroes/Conjecture.cpp b/8.16/S-TrailingZeroes/Conjecture.cpp
new file mode 100644
index 0000000..8e82d10
--- /dev/null
+++ b/8.16/S-TrailingZeroes/Conjecture.cpp
@@ -0,0 +1,49 @@
+#include <iostream>
+#include<cstdio>
+#include<algorithm>
+#include <cmath>
+#include <cstdlib>
+using namespace std;
+const int N=1e7+5;
+int pr[N/10];//存质数
+bool b[N];//是不是质数 
+int q,n;
+int t1=0,t;
+int cnt=0;
+void prime()
+{
+	for(int i=2;i<N;i++)
+	{
+		if(!b[i])
+		{
+			pr[++cnt]=i;
+		}
+		for(int j=1;j<=cnt&&pr[j]*i<N;j++)
+		{
+			b[pr[j]*i]=1;
+			if(i%pr[j]==0)
+			{
+				break;
+			}
+		}
+	} 
+}
+void ce()
+{
+	cout<<cnt;
+//	for(int i=1;i<=cnt;i++)
+//	{
+//		cout<<pr[i]<<" ";
+//	}
+}
+int main()
+{
+	prime();
+	ce();
+//	scanf("%d",&t);
+//	while(t--)
+//	{
+//		scanf("%d",&n);
+//	}
+	return 0;
+}