View Compilation Error

0_0_18506539_11283.cpp: In function 'int main()':
0_0_18506539_11283.cpp:58:7: error: expected primary-expression before 'if'
   if (if (!check(sum - m, n)) {
       ^
0_0_18506539_11283.cpp:58:7: error: expected ')' before 'if'