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

typedef enum op {
	ADD = '+',
	SUB = '-',
	MUL = '*',
	DIV = '/',
} op;

typedef struct ast {
	op o;
	int val1;
	struct ast *child1;

	int val2;
	struct ast *child2;
} ast;

int main(){
        FILE *f = fopen("test.in", "r");
	char *expr = malloc(256);
	fgets(expr, 256, f);

	for (int i = 0; i < strlen(expr); i++){

	}
}