View Compilation Error

0_0_26579525_10366.cpp:4:1: error: 'll' does not name a type
 ll read() {
 ^
0_0_26579525_10366.cpp:26:1: error: 'ostream' does not name a type
 ostream &operator<<(ostream &o, pii xx) {
 ^
0_0_26579525_10366.cpp: In function 'int main()':
0_0_26579525_10366.cpp:38:5: error: 'll' was not declared in this scope
     ll t=read();
     ^
0_0_26579525_10366.cpp:39:8: error: expected ';' before 'n'
     ll n;
        ^
0_0_26579525_10366.cpp:41:11: error: 't' was not declared in this scope
     while(t--){
           ^
0_0_26579525_10366.cpp:42:9: error: 'n' was not declared in this scope
         n=read();
         ^
0_0_26579525_10366.cpp:42:16: error: 'read' was not declared in this scope
         n=read();
                ^