#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;

int main(){
    int n;
    cin>>n;

    vector<long long> v(n),sp(n);

    for(auto&& r : v) cin>>r;
    for(int i=0;i<n;++i){ int x; cin>>x; v[i]-=x; }

    sp[0]=v[0];
    for(int i=1;i<n;++i) sp[i]=sp[i-1]+v[i];

    int mx=0;

    unordered_map<long long, int> um;
    um[0]=-1;

    for(int i=0;i<n;++i){
        if(um.find(sp[i]) != um.end()){
            int l = i-um[sp[i]];
            mx = max( mx, l);
        }
        else um[sp[i]]=i;
    }

    cout<<mx<<'\n';
}