View Compilation Error

0_0_7974772_1376.cpp: In function `int main()':
0_0_7974772_1376.cpp:15: error: `stack' undeclared (first use this function)
0_0_7974772_1376.cpp:15: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7974772_1376.cpp:15: error: expected primary-expression before "int"
0_0_7974772_1376.cpp:15: error: expected `;' before "int"
0_0_7974772_1376.cpp:19: error: `s' undeclared (first use this function)