#include <stdio.h>

typedef struct rational {
  int a;
  int b;
} RATIONAL;

int gcd(int a, int b){
  int r;

  if ( a < 0 ){
    a *= -1;
  }
  if ( b < 0 ){
    b *= -1;
  }

  r = a % b;
  while ( r != 0 ){
    a = b;
    b = r;
    r = a % b;
  }

  return b;
}

void reduce(RATIONAL *p){
  int c;
  c = gcd(p->a, p->b);

  p->a /= c;
  p->b /= c;
}

RATIONAL add(RATIONAL x, RATIONAL y){
  RATIONAL z;

  z.a = (x.a * y.b) + (y.a * x.b);
  z.b = x.b * y.b;

  reduce(&z);
  return z;
}

RATIONAL sub(RATIONAL x, RATIONAL y){
}

RATIONAL mul(RATIONAL x, RATIONAL y){
  RATIONAL z;

  z.a = x.a * y.a;
  z.b = x.b * y.b;

  reduce(&z);
  return z;
}

RATIONAL div(RATIONAL x, RATIONAL y){
}

void print_r(RATIONAL x ){
  printf("%d/%d", x.a, x.b);
}

void print_expression(RATIONAL x, RATIONAL y, RATIONAL z, char *op){
  print_r(x);
  printf(" %s ", op);
  print_r(y);
  printf(" = ");
  print_r(z);
  printf("\n");
}

int main(void){
  RATIONAL x, y;

  printf("有理数 x の分子と分母を入力してください：");
  scanf("%d %d", &(x.a), &(x.b));
  reduce(&x);

  printf("有理数 y の分子と分母を入力してください：");
  scanf("%d %d", &(y.a), &(y.b));
  reduce(&y);

  print_expression(x, y, add(x,y), "+");
  print_expression(x, y, sub(x,y), "-");
  print_expression(x, y, mul(x,y), "*");
  print_expression(x, y, div(x,y), "/");

  return 0;
}