import std.stdio, std.array, std.string, std.conv, std.algorithm;
import std.typecons, std.range, std.random, std.math, std.container;
import std.numeric, std.bigint, core.bitop;

immutable int INF = 10^^9;

void main() {
    auto N = readln.chomp.to!int;
    auto A = readln.split.map!(to!int).array;

    auto dp = new int[][](N, 2);
    foreach (i; 0..N) dp[i][0] = -INF;
    foreach (i; 0..N) dp[i][1] =  INF;
    dp[0][0] = max(A[0], -A[0]);
    dp[0][1] = min(A[0], -A[0]);

    foreach (i; 0..N-1) {
        foreach (j; 0..2) {
            dp[i+1][0] = max(dp[i+1][0], dp[i][j] + A[i+1]);
            dp[i+1][0] = max(dp[i+1][0], dp[i][j] - A[i+1]);
            dp[i+1][0] = max(dp[i+1][0], dp[i][j] * A[i+1]);
            if (A[i+1] != 0) dp[i+1][0] = max(dp[i+1][0], dp[i][0] / A[i+1]);
        
            dp[i+1][1] = min(dp[i+1][1], dp[i][j] + A[i+1]);
            dp[i+1][1] = min(dp[i+1][1], dp[i][j] - A[i+1]);
            dp[i+1][1] = min(dp[i+1][1], dp[i][j] * A[i+1]);
            if (A[i+1] != 0) dp[i+1][1] = min(dp[i+1][1], dp[i][j] / A[i+1]);
        }
    }

    writeln(dp[N-1][0]);
}