TIOJ 1411

#include <cstdio>
#include <algorithm>
inline char readchar() {
    constexpr int B = 1<<20;
    static char buf[B], *p=buf, *q=buf;
    if(p == q && (q=(p=buf)+fread(buf,1,B,stdin)) == buf) return EOF;
    return *p++;
}
inline int nextint() {
    bool neg=false;
    int x = 0, c = readchar();
    while(('0'>c||c>'9')&&c!='-'&&~c) c = readchar();
    if(c=='-') neg=true, c=readchar();
    while('0'<=c&&c<='9') x=x*10+c-'0', c=readchar();
    if(neg) x = -x;
    return x;
}
int n,id[1000001];
long long v[1000001];
signed main() {
    while(n = nextint()) {
        for(int i = 1; i <= n; i++) v[i] = nextint();
        for(int i = 1; i <= n; i++) v[i] = (v[i] > 0 ? 1 : v[i] < 0 ? -1 : 0) + v[i-1];
        for(int i = 0; i <= n; i++) id[i] = i;
        std::stable_sort(id,id+n+1,[](int a,int b){return v[a]<v[b];});
        //for(int i = 0; i <= n; i++) printf("%d%c", id[i], " \n"[i==n]);
        //for(int i = 0; i <= n; i++) printf("%d%c", v[id[i]], " \n"[i==n]);
        int ans = 0;
        for(int i = 0, j; i <= n; i = j) {
            for(j = i+1; j <= n; j++) if(v[id[j]]!=v[id[i]]) break;
            //printf("%d %d\n", id[j], id[i]);
            ans = std::max(ans, id[j-1] - id[i]);
        }
        printf("%d\n", ans);
    }
}