I have this code but here atoi does not work at all 
If i gave base address then also it causes prob

```
int main()
{
    char *token;
    int value;
    char data = "23+100";
    int i = 0;
    while(data[i] != '+' )
    {
        value = atoi(data[i]);
        push(value,&top1);
        i++;
    }
}

```