C.cpp

#include<bits/stdc++.h>
#define vi vector<int>
#define ma map<int,int>
#define uma unordered_map <int,int>
#define ll long long int
#define pb push_back
#define mod 1000000007
#define int long long
#define  loop(i,x,n) for(int i=x;i<n;i++)
#define rloop(i,n) for(int i=n-1;i>=0;i--)
#define test int t;cin>>t; while(t--)
#define mp make_pair
#define pr pair<int,int>
using namespace std;
/*************************************************************************************************/
int n; 
int dp[105][200005];                                                                    
bool equal(int i,int a[],int s,int j)
{
    if(i==n)
    return false;
    if(s==0)
    return true;
    if(dp[i][s]!=-1)
    return dp[i][s];
    if(s>=a[i] && i!=j)
    return dp[i][s]=equal(i+1,a,s-a[i],j) || equal(i+1,a,s,j);
    else 
    return dp[i][s]=equal(i+1,a,s,j);
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int sum=0;
    cin>>n;
    int a[n];
    loop(i,0,n)
    {
        cin>>a[i];
        sum+=a[i];
    }
    memset(dp,-1,sizeof(dp));
    bool b=true;
    if(sum%2 || !equal(0,a,sum/2,-1))
    b=false;
    if(!b)
    cout<<0;
    else
    {
        cout<<"1\n";
        for(int i=0;i<n;i++)
        {
            if(a[i]%2)
            {
                cout<<i+1;
                return 0;
            }
            //memset(dp,-1,sizeof(dp));
            if((sum-a[i])%2 || !equal(0,a,(sum-a[i])/2,i))
            {
                cout<<i+1;
                //cout<<endl<<!equal(0,a,(sum-a[i])/2,i);
                return 0;
            }

            
        }
    }
    return 0;
}