It doesn’t work

#include <iostream>
#include <cmath>
#include <vector>

using namespace std;
ostream & operator<<(ostream & out, vector<int> const & v)
{
    for (int el: v)
        out<< el <<' ';
    return out;
}
int main()
{
    long long int q,n,    x,  a10,   a5,  a2, a1, answer,  l   ,u  ,t,N,K,    i,summ,m,k,o;
    vector<int> a;
    summ=0;
    q=0;
    o=0;
    cin >> n >> k >> m;
    for (i=0;i<n;++i)
    {
        cin >> x;
        a.push_back(x);
    }
    for (i=0;i<n+1;++i)
    {
       // cout<<"     "<<i<<endl;
        if(((i+q)!=(k+q+1)) & i+q<n & (int(i==0)*(n-(i+q)-1)+int(i!=0)*k+1)>=k)
        {
            summ+=a[i+q];
        }
        else
        {
            if(summ==m)
            {
                o=q+1;
                break;
            }
            i=-1;
            ++q;
            summ=0;
        }
        if (q==n) break;

    }
    cout<<o;
    return 0;
}