func_code_string: #include<bits/stdc++.h>   #define rep(i,a,b) for(long long i=a;i<b;i++)   #define pb push_back   #define f first   #define s second   #define is insert   #define vector_int vector<int>   #define ll long long   #define pqi priority_queue<int>   #define all(x) x.begin(),x.end()   #define mem(x,y) memset(x,y,sizeof(x))   #define sz(x) (int)x.size()   #define pii pair<int,int>   #define pll pair<ll,ll>   #define INF 1e9   #define INFL 1e18   #define mod 1000000007   #define fast ios::sync_with_stdio(false);cin.tie(0);   using namespace std;      int equalPartition(int n, vector<int> arr)       {           int sum = 0;       int i, j;           // Calculate sum of all elements       for (i = 0; i < n; i++)           sum += arr[i];           if (sum % 2 != 0)           return false;           bool part[sum / 2 + 1][n + 1];           // initialize top row as true       for (i = 0; i <= n; i++)           part[0][i] = true;           // initialize leftmost column,       // except part[0][0], as 0       for (i = 1; i <= sum / 2; i++)           part[i][0] = false;           // Fill the partition table in bottom up manner       for (i = 1; i <= sum / 2; i++) {           for (j = 1; j <= n; j++) {               part[i][j] = part[i][j - 1];               if (i >= arr[j - 1])                   part[i][j] = part[i][j]                                || part[i - arr[j - 1]][j - 1];           }       }           /* // uncomment this part to print table       for (i = 0; i <= sum/2; i++)       {       for (j = 0; j <= n; j++)           cout<<part[i][j];       cout<<endl;       } */           return part[sum / 2][n];       }      void solve(){       ll n=0;cin>>n;       vector<int> arr;       for(int i=0;i<n;i++) {           int x;           cin>>x;           arr.pb(x);       }       if(equalPartition( n,arr)==0) cout<<0<<endl;       else {           for(int i=0;i<n;i++){               int x=arr[i];               arr[i]=0;               if(equalPartition(n,arr)==0) {                   cout<<1<<endl<<i+1<<endl;                   break;               }               else{                   arr[i]=x;               }           }       }   }       int main() {                  solve();              return 0;   }