diff --git a/src/week1/BOJ4375/BOJ4375_V1.cpp b/src/week1/BOJ4375/BOJ4375_V1.cpp
new file mode 100644
index 0000000..a282972
--- /dev/null
+++ b/src/week1/BOJ4375/BOJ4375_V1.cpp
@@ -0,0 +1,31 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+
+    int n;
+
+
+    while (scanf("%d", &n) != EOF) {
+        int cnt = 1;
+        ll ret = 1;
+        while(true) {
+            if (ret % n == 0) {
+                cout << cnt << "\n";
+                break;
+            } else {
+                ret = (ret * 10) + 1;
+                ret %= n;
+                cnt++;
+            }
+        }
+    }
+
+
+
+
+    return 0;
+}
\ No newline at end of file