func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 1e9 + 7;   const long long llinf = 1e18 + 7;   const double eps = 1e-15;   const int mod = 1e9 + 7;   int main() {     ios::sync_with_stdio(false);     int n, a[100001], k;     cin >> n >> k;     for (int i = 1; i <= n; i++) cin >> a[i];     int i = n;     while (i > 0 && a[n] == a[i]) i--;     if (i >= k)       cout << -1;     else       cout << i;     return 0;   }   