View Compilation Error

0_0_4144373_8637.cpp: In function `int main()':
0_0_4144373_8637.cpp:14: error: `string' undeclared (first use this function)
0_0_4144373_8637.cpp:14: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4144373_8637.cpp:14: error: expected `;' before "str"
0_0_4144373_8637.cpp:15: error: `str' undeclared (first use this function)
0_0_4144373_8637.cpp:18: error: `len' undeclared (first use this function)