#include <bits/stdc++.h>  // This will work only for g++ compiler. 
#define for0(i, n) for (int i = 0; i < (int)(n); ++i) // 0 based indexing
#define for1(i, n) for (int i = 1; i <= (int)(n); ++i) // 1 based indexing
#define forc(i, l, r) for (int i = (int)(l); i <= (int)(r); ++i) // closed interver from l to r r inclusive
#define forr0(i, n) for (int i = (int)(n) - 1; i >= 0; --i) // reverse 0 based.
#define forr1(i, n) for (int i = (int)(n); i >= 1; --i) // reverse 1 based
//short hand for usual tokens
#define pb push_back
#define fi first
#define se second
// to be used with algorithms that processes a container Eg: find(all(c),42)
#define all(x) (x).begin(), (x).end() //Forward traversal
#define rall(x) (x).rbegin, (x).rend() //reverse traversal
// traversal function to avoid long template definition. Now with C++11 auto alleviates the pain.
#define tr(c,i) for(__typeof__((c)).begin() i = (c).begin(); i != (c).end(); i++)
// find if a given value is present in a container. Container version. Runs in log(n) for set and map
#define present(c,x) ((c).find(x) != (c).end())
//find version works for all containers. This is present in std namespace.
#define cpresent(c,x) (find(all(c),x) != (c).end())
// Avoiding wrap around of size()-1 where size is a unsigned int.
#define sz(a) int((a).size())
using namespace std;
// Shorthand for commonly used types
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef double ld;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    int t;
    cin >> t;
    while(t--){
        ll n; cin >> n;
        if(n < 2050 || n%(2050) != 0){
            cout << "-1" << endl;
            continue;
        }
        ll x = n/2050;
        int count = 0;
        while(x>=10){
            
            count+=(x%10);
            x = x/10;
        }
        if(x<10){
            count += x;
        }
        
        cout << count << endl;
    }   
}