diff --git a/Hydro/bzoj/1257/1257.cpp b/Hydro/bzoj/1257/1257.cpp
index 0e03d09a..6c149f92 100644
--- a/Hydro/bzoj/1257/1257.cpp
+++ b/Hydro/bzoj/1257/1257.cpp
@@ -10,8 +10,9 @@ long long n, k, ans;
 int main() {
     cin >> n >> k;
     ans = n * k;
-    for (int x = 1; x <= n; x++) {
-        ans -= floor(1.0 * k / x) * x;
+    for (int x = 1, gx; x <= n; x = gx + 1) {
+        gx = k / x ? std::min(k / (k / x), n) : n;
+        ans -= (k / x) * (x + gx) * (gx - x + 1) / 2;
     }
     cout << ans << endl;
     return 0;