for (int i = 0; i < 1000; i++) {

Console.WriteLine ("input num0");

string str0 = Console.ReadLine ();

int num0;

bool flag0 = int.TryParse (str0,out num0);

if (flag0) {

for (int j = 0; j < 1000; j++) {

Console.WriteLine ("input num1");

string str1 = Console.ReadLine ();

int num1;

bool flag1 = int.TryParse (str1, out num1);

if (flag1) {

for (int k = 0; k < 1000; k++) {

Console.WriteLine ("input num2");

string str2 = Console.ReadLine ();

int num2;

bool flag2 = int.TryParse (str2, out num2);

if (flag2) {

int max = num0 > num1 ? num0 : num1;

max = max > num2 ? max : num2;

Console.WriteLine ("max =" + max);

break;

} else {

Console.WriteLine ("num2 wrong,again input");

continue;

}

}break;

} else {

Console.WriteLine ("num1 wrong,again input");

continue;

}

}

} else {

Console.WriteLine ("num0 wrong,again input");

continue;

}

}