View Compilation Error

0_0_7473449_24565.cpp: In function `int main()':
0_0_7473449_24565.cpp:21: error: `c' undeclared (first use this function)
0_0_7473449_24565.cpp:21: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7473449_24565.cpp:21: error: expected `;' before "printf"