View Compilation Error

0_0_30933827_9593.cpp: In function 'int main()':
0_0_30933827_9593.cpp:27:58: error: invalid initialization of non-const reference of type 'int&' from an rvalue of type 'int'
                 if(i>j) gmax(f[i][j],sum[i] - sum[i-j-1] - f[i-j-1][j+1]); 
                                                          ^
0_0_30933827_9593.cpp:8:6: note: in passing argument 2 of 'void gmax(int&, int&)'
 void gmax(int &a,int &b){
      ^