View Compilation Error

259302_0_7285.cpp: In function `int gcd(int, int)':
259302_0_7285.cpp:5: error: `n' undeclared (first use this function)
259302_0_7285.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
259302_0_7285.cpp:5: error: `m' undeclared (first use this function)