#include <atcoder/math> #include <iostream> #include <stdio.h> #include <vector> #include <utility> #include <algorithm> using namespace std; using namespace atcoder; #define ll long long #define Pll pair<ll,ll> signed main(){ ll N,M,K,ans=1000000000000; cin>>N>>M; vector<ll> A(N); vector<ll> B(M); vector<ll>r(2); vector<ll>m={N,M}; for(ll i=0;i<N;i++)cin>>A.at(i); for(ll i=0;i<M;i++)cin>>B.at(i); for(ll i=0;i<N;i++)for(ll j=0;j<M;j++){ if(A.at(i)==B.at(j)){ r.at(0)=i+1; r.at(1)=j+1; Pll a=crt(r,m); ans=min(ans,a.first%a.second); } } if(ans==1000000000000)printf("-1\n"); else printf("%lld\n",ans); return 0; }