Maximum sum

cc1plus: error: '::main' must return 'int'

#include <bits/stdc++.h>
using namespace std;

long main() {
    long n;
    cin >> n;
    vector<long> v;
    for (long i = 0; i < n; i++) {
        long t;
        cin >> t;
        v.push_back(t);
    }

    long long max = 0;
    for (long i = 0; i < n; i++) {
        long j = 0;
        long k = i;
        long long currSum = 0;
        for (long p = j; p <= k; p++) currSum += v[p];
        if (currSum > max) max = currSum;
        for (; k < n; j++, k++) {
            if (j == 0) continue;
            currSum -= v[j-1];
            currSum += v[k];
            if (currSum > max) max = currSum;
        }
    }

    cout << max;
}