#473. 简单的数学题

https://sjzezoj.com/submission/13575

S2OJ/473/473.cpp

@@ -0,0 +1,24 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int mod = 998244353;
+
+long long n, m;
+
+long long phi(long long x) {
+    long long ans = x;
+    for (long long i = 2; i * i <= x; i++)
+        if (x % i == 0) {
+            ans = ans / i * (i - 1);
+            while (x % i == 0) x /= i;
+        }
+    if (n > 1) ans = ans / x * (x - 1);
+    return ans;
+}
+
+int main() {
+    scanf("%lld%lld", &n, &m);
+    printf("%lld\n", (long long)(n % mod) * (m % mod) % mod * (phi(n) % mod) % mod * (phi(m) % mod) % mod);
+    return 0;
+}