1 files changed, 25 insertions, 0 deletions
diff --git a/works/life/algorithm-experiment/5.1b.cpp b/works/life/algorithm-experiment/5.1b.cpp
new file mode 100644
index 0000000..a6dd32e
--- /dev/null
+++ b/works/life/algorithm-experiment/5.1b.cpp
@@ -0,0 +1,25 @@
+#include <bitset>
+#include <ios>
+#include <iostream>
+
+std::bitset<10000000> f;
+
+int main() {
+  std::ios_base::sync_with_stdio(false);
+  std::cin.tie(nullptr);
+
+  long long current;
+
+  while (std::cin >> current) {
+    f[current - 10000000].flip();
+  }
+
+  for (int i = 1; i < 10000000; ++i) {
+    if (f[i]) {
+      std::cout << i + 10000000;
+      break;
+    }
+  }
+
+  return 0;
+}