#include <stdio.h>

#include <stdlib.h>

extern int yylex();

extern int yyparse();

extern FILE* yyin;

void yyerror(long long*, const char* s);

%parse-param { long long* result }

%union {

long long val;

}

%token<val> T_NUM

%token T_PLUS T_MULTIPLY T_LEFT T_RIGHT T_NEWLINE

// part 1

%left T_MULTIPLY T_PLUS

// part 2

// %left T_MULTIPLY

// %left T_PLUS

%type<val> expression

%start calculation

calculation:

| calculation line

;

line: T_NEWLINE

| expression T_NEWLINE { *result += $1; }

;

expression: T_LEFT expression T_RIGHT { $$ = $2; }

| expression T_PLUS expression { $$ = $1 + $3; }

| expression T_MULTIPLY expression { $$ = $1 * $3; }

| T_NUM { $$ = $1; }

;

int main() {

yyin = stdin;

do {

long long result = 0;

yyparse(&result);

printf("%lld\n", result);

} while(!feof(yyin));

return 0;

}

void yyerror(long long* answer, const char* s) {

fprintf(stderr, "Parse error: %s\n", s);

exit(1);

}