View Compilation Error

0_0_20099009_32662.c: In function 'main':
0_0_20099009_32662.c:9:10: error: 'input' undeclared (first use in this function)
    int a=input.nextInt();
          ^
0_0_20099009_32662.c:9:10: note: each undeclared identifier is reported only once for each function it appears in