View Compilation Error

0_0_10920572_10394.cpp: In function `int main()':
0_0_10920572_10394.cpp:27: error: `a' undeclared (first use this function)
0_0_10920572_10394.cpp:27: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_10920572_10394.cpp:27: error: expected `;' before "int"
0_0_10920572_10394.cpp:28: error: `t' undeclared (first use this function)