using static System.Console;
using static System.Math;
 
namespace Vetor1 {
	class Program {
        static int Main(string[] args) {
            var vetor = new int[10];
            for (int i = 0; i < vetor.Length; i++) {
                do {
					Write($"Digite o {i}° número: ");
					if (!int.TryParse(ReadLine(), out vetor[i])) {
						WriteLine("Valor inválido, tente de novo.");
						continue;
                    }
                } while (vetor[i] < -1);
            }
            for (int i = 0; i < vetor.Length; i++) if (EhPrimo(vetor[i])) WriteLine($"Posição {i}");
            return 0;
        }
		public static bool EhPrimo(int numero) {
			if (numero <= 1) return false;
			if (numero == 2) return true;
			if (numero % 2 == 0) return false;
			var limite = (int)Floor(Sqrt(numero));
			for (int i = 3; i <= limite; i += 2) if (numero % i == 0) return false;
			return true;        
		}
    }
}
 
//https://pt.stackoverflow.com/q/412410/101

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