/*

E ::= T{+T}
T ::= F{*F}
F ::= (E)|i

*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>


#define eprintf(...) fprintf(stderr, __VA_ARGS__)


typedef enum TokenType {
    INT,
    PLUS,
    MINUS,
    LBRACE,
    RBRACE
} TokenType;

typedef struct _Token {
    TokenType type;

    int value;
} Token;


void fatal(const char* message);
void scan();

void e();
void t();
void f();


const int LINE_MAX = 1024;
char *line;

int symbol;
int char_num = 0;


int main(int argc, char* argv[]) {
    line = calloc(sizeof(char), LINE_MAX);
    memset(line, 0, LINE_MAX);

    scan();
    e();

    if (symbol != '\n') {
        fatal("Syntax invalid");
    }

    printf("Success\n");

    free(line);
    return 0;
}

void scan() {
    symbol = getchar();
    if (symbol == '\n')
        line[char_num++] = ' ';
    else
        line[char_num++] = symbol;
}

void e() {
    t();
    while (symbol == '+') {
        scan();
        t();
    }
}

void t() {
    f();
    while (symbol == '*') {
        scan();
        f();
    }
}

void f() {
    if (symbol == '(') {
        scan();
        e();
        if (symbol != ')') {
            fatal("Expected parentheses");
        }
    }
    else if (symbol >= '0' && symbol <= '9') {
        ;
    }
    else if (symbol == '\n') {
        fatal("LF too early");
    }
    else {
        fatal("Unexpected symbol");
    }
    scan();
}

void fatal(const char* message) {
    eprintf("\nError at char %d\n%s\n", char_num, line);
    eprintf("%*c\n", char_num, '^');
    eprintf("Message: %s\n", message);
    exit(1);
}