diff --git a/zeta_python/2981.py b/zeta_python/2981.py
deleted file mode 100644
index 676a0e8..0000000
--- a/zeta_python/2981.py
+++ /dev/null
@@ -1,9 +0,0 @@
-N = int(input())
-I = sorted([int(input())for i in range(N)])
-p = min([(j-i) for i, j in zip(I, I[1:])])
-print(p)
-T = [t for t in range(1, int(p**(1/2))+1) if p % t == 0]
-if T[-1] == p // T[-1]:
-    print(" ".join([str(t) for t in T[1:-1]] + [str(p // t) for t in T[::-1]]))
-else:
-    print(" ".join([str(t) for t in T[1:]] + [str(p // t) for t in T[::-1]]))
diff --git a/zeta_python/completed/1676.py b/zeta_python/completed/1676.py
new file mode 100644
index 0000000..b5aa85b
--- /dev/null
+++ b/zeta_python/completed/1676.py
@@ -0,0 +1,20 @@
+def solve(N):
+    if N == 0 or N == 1:
+        return 0
+    count2 = 0
+    count5 = 0
+
+    for i in range(2, N + 1):
+        while i % 2 == 0 or i % 5 == 0:
+            if i % 2 == 0:
+                i //= 2
+                count2 += 1
+            elif i % 5 == 0:
+                i //= 5
+                count5 += 1
+
+    return min((count2, count5))
+
+
+if __name__ == '__main__':
+    print(solve(int(input())))
diff --git a/zeta_python/completed/1676_shortcut.py b/zeta_python/completed/1676_shortcut.py
new file mode 100644
index 0000000..85d7e21
--- /dev/null
+++ b/zeta_python/completed/1676_shortcut.py
@@ -0,0 +1,16 @@
+def solve(N):
+    if N == 0 or N == 1:
+        return 0
+    count5 = 0
+
+    for i in range(5, N + 1, 5):
+        while i % 5 == 0:
+            if i % 5 == 0:
+                i //= 5
+                count5 += 1
+
+    return count5
+
+
+if __name__ == '__main__':
+    print(solve(int(input())))
diff --git a/zeta_python/completed/2981.py b/zeta_python/completed/2981.py
new file mode 100644
index 0000000..c089f54
--- /dev/null
+++ b/zeta_python/completed/2981.py
@@ -0,0 +1,32 @@
+def divisor(x):
+    divs = []
+    for i in range(1, int(x ** (1 / 2)) + 1):
+        if x % i == 0:
+            divs.append(i)
+    for d in divs[::-1]:
+        t = x // d
+        if d == t:
+            continue
+        divs.append(x // d)
+    return divs
+
+
+def gcd(x1, x2):
+    while x2 != 0:
+        temp = x1 % x2
+        x1 = x2
+        x2 = temp
+    return x1
+
+
+def solve(N, M):
+    M.sort()
+    last_night = M[1] - M[0]
+    for i in range(1, N - 1):
+        last_night = gcd(last_night, M[i + 1] - M[i])
+    return " ".join(map(str, divisor(last_night)[1:]))
+
+
+if __name__ == '__main__':
+    n = int(input())
+    print(solve(n, list(map(int, (input() for i in range(n))))))
diff --git a/zeta_python/completed/3036.py b/zeta_python/completed/3036.py
new file mode 100644
index 0000000..4afe6fe
--- /dev/null
+++ b/zeta_python/completed/3036.py
@@ -0,0 +1,24 @@
+def fraction_ize(p, q):
+    while True:
+        # one process
+        for i in range(2, int(max((p, q)) ** (1 / 2)) + 1):
+            if q % i == 0:
+                if p % i == 0:
+                    q //= i
+                    p //= i
+                    break
+        else:
+            break
+    return p, q
+
+
+def solve(N, M):
+    chains = M[0]
+    T = []
+    for i in range(1, N):
+        T.append(fraction_ize(chains, M[i]))
+    return "\n".join(f"{p}/{q}" for p, q in T)
+
+
+if __name__ == '__main__':
+    print(solve(int(input()), list(map(int, input().split()))))