View Compilation Error

0_0_13631010_13933.cpp: In function 'int main()':
0_0_13631010_13933.cpp:5:13: error: 'sf' was not declared in this scope
  sf("%d", &n);
             ^
0_0_13631010_13933.cpp:21:10: error: expected '}' at end of input
  return 0;
          ^