Sum in C -- FI

#include<stdio.h>

int main(){

    int a;
    char symbol;
    int b;
    int c = a + b;

    printf("Enter digit\n");
     while(scanf("%d",&a) != 1)
    {
        printf("Please enter an integer: ");
        while(getchar() != '\n');
    }
    //scanf(" %d", &a);
    printf("Enter + symbol\n");
    fflush(stdin);
    scanf(" %c", &symbol);
    printf("Enter digit\n");
   // scanf(" %d", &b);
     while(scanf("%d",&b) != 1)
    {
        printf("Please enter an integer: ");
        while(getchar() != '\n');
    }
    if(symbol == '+'){
            int sum;
    sum = a + b;
        printf(" %d\n\n", sum);
    }

    printf("---------------------------------\n");
    printf("---------------------------------\n");
    printf("\n");

    printf("a: %d b: %d c: %c\n", a,b,symbol);


    return 0;
}