View Compilation Error

0_0_29982528_30293.cpp: In function 'int main()':
0_0_29982528_30293.cpp:119:45: error: no matching function for call to 'MCMF::solve(int&, int&, const int&, int&)'
         cout << -mcmf.solve(s1, t, inf, flow) << endl;
                                             ^
0_0_29982528_30293.cpp:119:45: note: candidate is:
0_0_29982528_30293.cpp:58:9: note: int MCMF::solve(int, int, int&, int)
     int solve(int s, int t, int &flow, int limit) {
         ^
0_0_29982528_30293.cpp:58:9: note:   no known conversion for argument 3 from 'const int' to 'int&'