View Compilation Error

0_0_1995074_25449.cpp: In function `int main()':
0_0_1995074_25449.cpp:5: error: `cin' undeclared (first use this function)
0_0_1995074_25449.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1995074_25449.cpp:7: error: `set' undeclared (first use this function)
0_0_1995074_25449.cpp:7: error: `string' undeclared (first use this function)
0_0_1995074_25449.cpp:7: error: `s1' undeclared (first use this function)
0_0_1995074_25449.cpp:7: error: `s2' undeclared (first use this function)
0_0_1995074_25449.cpp:10: error: expected `;' before "q"
0_0_1995074_25449.cpp:11: error: `q' undeclared (first use this function)
0_0_1995074_25449.cpp:11: error: `w' undeclared (first use this function)
0_0_1995074_25449.cpp:16: error: `puts' undeclared (first use this function)