View Compilation Error

0_0_38050485_1932.cpp:4:1: error: 'string' does not name a type
 string a[1000100];
 ^
0_0_38050485_1932.cpp: In function 'int main()':
0_0_38050485_1932.cpp:11:16: error: 'a' was not declared in this scope
    getline(cin,a[i]); int m = a[i].size();
                ^