#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")

int n, niz[105], br, maks=0;

int main(){
    //ios_base::sync_with_stdio(false); cin.tie(0);
    freopen("operationsJ.in", "r", stdin);
    freopen("operationsJ.out", "w", stdout);

    cin>>n;
    for(int i=0; i<n; i++){
        scanf("%d", &br);
        if(br<0)
            br=-br;
        if(br>maks)
            maks=br;
        if(maks==100)
            break;
    }
    cout<<maks<<endl;
    return 0;
}