where the fuck is error

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#pragma warning (disable:4996)

int main()
{
  char num1, num2;
  int opchar;
  int ch1, ch2;
  int ans;
  int opOK;

    do{
        ch1 = ch2 = num1 = num2 = ans = 0;

        do{
        num1 = getchar();
        switch(num1)
        {
        case 'M':
        case 'm':
            ch1 += 1000;
            break;
        case 'D':
        case 'd':
            ch1 += 500;
            break;
        case 'C':
        case 'c':
            ch1 += 100;
            break;
        case 'L':
        case 'l':
            ch1 += 50;
            break;
        case 'X':
        case 'x':
            ch1 += 10;
            break;
        case 'V':
        case 'v':
            ch1 += 5;
            break;
        case 'I':
        case 'i':
            ch1 =+ 1;
            break;
        default:
            break;
        }
    }
  while(num1 != 'Q' && num1 !='q');

    do{
        num2 = getchar();
        switch(num2)
        {
        case 'M':
        case 'm':
            ch1 += 1000;
            break;
        case 'D':
        case 'd':
            ch1 += 500;
            break;
        case 'C':
        case 'c':
            ch1 += 100;
            break;
        case 'L':
        case 'l':
            ch1 += 50;
            break;
        case 'X':
        case 'x':
            ch1 += 10;
            break;
        case 'V':
        case 'v':
            ch1 += 5;
            break;
        case 'I':
        case 'i':
            ch1 =+ 1;
            break;
        default:
            break;
        }
    }
  while(num2 != 'Q' && num2 !='q');

    do{
        opchar = getchar();

        switch(opchar)
        {
        case '+':
            ans = ch1 + ch2;
            opOK = true;
            break;
        case '-':
            ans = ch1 - ch2;
            opOK = true;
            break;
        case '*':
            ans = ch1 * ch2;
            opOK = true;
            break;
        case '/':
            if(num2 ==0)
            {
                printf("\n-\n");
                opOK = false;
                break;
            }
            else
            {
                ans = ch1 / ch2;
                opOK = true;
                break;
            }
defalut:
            printf("-\n");
            opOK = false;
        }
    }
  while(opOK != true);
  printf("\n%d\n", ans);

    if(ans < 0)
    {
        printf("-");
        ans *= -1;
    }
    while(ans >= 1000)
    {
        printf("M");
        ans -= 1000;
    }
    while(ans >= 500)
    {
        printf("D");
        ans -= 500;
    }
    while(ans >= 100)
    {
        printf("C");
        ans -= 100;
    }
    while(ans >= 50)
    {
        printf("L");
        ans -= 50;
    }
    while(ans >= 10)
    {
        printf("X");
        ans -= 10;
    }
    while(ans>= 5)
    {
        printf("V");
        ans -= 5;
    }
    while(ans >= 1)
    {
        printf("I");
        ans -= 1;
    }

    }
}