View Compilation Error

0_0_37730798_20023.cpp: In function 'T read()':
0_0_37730798_20023.cpp:7:5: error: 'RG' was not declared in this scope
     RG int f = 1;
     ^
0_0_37730798_20023.cpp:8:8: error: expected ';' before 'T'
     RG T sum = 0;
        ^
0_0_37730798_20023.cpp:9:8: error: expected ';' before 'char'
     RG char ch = getchar();
        ^
0_0_37730798_20023.cpp:10:21: error: 'ch' was not declared in this scope
     while (!isdigit(ch)) {
                     ^
0_0_37730798_20023.cpp:11:24: error: 'f' was not declared in this scope
         if (ch == '-') f = -1;
                        ^
0_0_37730798_20023.cpp:14:20: error: 'ch' was not declared in this scope
     while (isdigit(ch)) {
                    ^
0_0_37730798_20023.cpp:15:9: error: 'sum' was not declared in this scope
         sum = (sum << 1) + (sum << 3) + (ch ^ 48);
         ^
0_0_37730798_20023.cpp:18:12: error: 'f' was not declared in this scope
     return f * sum;
            ^
0_0_37730798_20023.cpp:18:16: error: 'sum' was not declared in this scope
     return f * sum;
                ^