'commit'

TangDou/AoSaiYiBenTong/YBT1015.cpp

@@ -0,0 +1,10 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    float r1, r2;
+    cin >> r1 >> r2;
+    printf("%.2f", 1.0 / (1.0 / r1 + 1.0 / r2));
+    return 0;
+}