Multiple Matrix multiplication in c

#include
int main()
{
int m, n, p, q, c, d, k, sum = 0;
int first[10][10], second[10][10], multiply[10][10];

printf("Enter the first matrix number of rows and columns \n");
scanf("%d%d", &m, &n);
printf("Enter elements\n");

for (c = 0; c < m; c++)
for (d = 0; d < n; d++)
scanf("%d", &first[c][d]);

printf("Enter the second matrix number of rows and columns\n");
scanf("%d%d", &p, &q);
if (n != p) printf("Not valid Matrix \n");
else {
printf("Enter elements \n");
for (c = 0; c < p; c++)
for (d = 0; d < q; d++)
scanf("%d", &second[c][d]);
for (c = 0; c < m; c++)
{
for (d = 0; d < q; d++)
{
for (k = 0; k < p; k++)
{
sum = sum + first[c][k]*second[k][d];
}
multiply[c][d] = sum; sum = 0;
}
}
printf("Result Is :-\n");
for (c = 0; c < m; c++)
{
for (d = 0; d < q; d++)
printf("%d\t", multiply[c][d]);
printf("\n");
}
}
return 0;}