new file: P1516.cpp

P1516.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+#define int long long
+int exgcd(int a, int b, int &x, int &y)
+{
+    if (b == 0)
+    {
+        x = 1, y = 0;
+        return a;
+    }
+    int ans = exgcd(b, a % b, y, x);
+    y -= a / b * x;
+    return ans;
+}
+signed main()
+{
+    // freopen("frog.in", "r", stdin);
+    // freopen("frog.out", "w", stdout);
+    int a, b, x, y, n, m, l;
+    scanf("%lld%lld%lld%lld%lld", &a, &b, &m, &n, &l);
+    int ans = exgcd(m - n, l, x, y), mod = abs(l / ans);
+    if ((b - a) % ans)
+    {
+        printf("Impossible\n");
+        return 0;
+    }
+    x = (x * ((b - a) / ans) % mod + mod) % mod;
+    printf("%lld\n", x);
+    return 0;
+}