View Compilation Error

0_0_5176488_15852.cpp: In function `void minflow()':
0_0_5176488_15852.cpp:89: error: `flow' undeclared (first use this function)
0_0_5176488_15852.cpp:89: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_5176488_15852.cpp: In function `int main()':
0_0_5176488_15852.cpp:130: error: `cost' undeclared (first use this function)