View Compilation Error

0_0_6768853_28106.cpp: In function `double cal(int)':
0_0_6768853_28106.cpp:7: error: integer constant is too large for "long" type
0_0_6768853_28106.cpp:7: error: integer constant is too large for "long" type
0_0_6768853_28106.cpp: At global scope:
0_0_6768853_28106.cpp:11: error: `main' must return `int'