View Compilation Error

0_0_38430550_6531.cpp: In function 'int main()':
0_0_38430550_6531.cpp:31:21: error: expected primary-expression before 'if'
                 if (if (a > 0 && a <= n && b > 0 && b <= n && c > 0 && c <= n && d > 0 && d <= n))
                     ^
0_0_38430550_6531.cpp:31:21: error: expected ')' before 'if'