View Compilation Error

0_0_29046364_8640.cpp: In function 'int main()':
0_0_29046364_8640.cpp:83:22: error: 'st1' was not declared in this scope
   scanf("%d%d%d%d", &st1, &en1, &st2, &en2);
                      ^
0_0_29046364_8640.cpp:83:28: error: 'en1' was not declared in this scope
   scanf("%d%d%d%d", &st1, &en1, &st2, &en2);
                            ^
0_0_29046364_8640.cpp:83:34: error: 'st2' was not declared in this scope
   scanf("%d%d%d%d", &st1, &en1, &st2, &en2);
                                  ^
0_0_29046364_8640.cpp:83:40: error: 'en2' was not declared in this scope
   scanf("%d%d%d%d", &st1, &en1, &st2, &en2);
                                        ^