View Compilation Error

0_0_6253671_2216\Main.java:8: cannot find symbol
symbol  : variable in
location: class Main
		int i , t = in.nextInt();
		            ^
0_0_6253671_2216\Main.java:9: i is already defined in main(java.lang.String[])
		for (int i = 0; i < t; i ++) 
		         ^
0_0_6253671_2216\Main.java:15: cannot find symbol
symbol  : variable in
location: class Main
				input = in.nextBigInteger();
				        ^
0_0_6253671_2216\Main.java:18: cannot find symbol
symbol  : variable sum
location: class Main
				sum = sum.add(input);
				^
0_0_6253671_2216\Main.java:18: cannot find symbol
symbol  : variable sum
location: class Main
				sum = sum.add(input);
				      ^
0_0_6253671_2216\Main.java:22: cannot find symbol
symbol  : variable sum
location: class Main
			System.out.println(sum);
			                   ^
6 errors