program for multiplication of two matrices by pointers

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int **p,**q,**s;
    int m1,m2,n1,n2,i,j,k=0,sum;
    printf("enter oreder of 1st matrix:");
    scanf("%d%d",&m1,&n1);
    printf("Enter order of 2nd matrix:");
    scanf("%d%d",&m2,&n2);
    if(m1!=n2)
              printf("Multiplication not possible.");
    else
    {
        printf("Enter elements of 1st matrix:");
        p=malloc(m1*sizeof(int*));
        for(i=0;i<m1;i++)
                p[i]=malloc(n1*sizeof(int));
        for(i=0;i<m1;i++)
                for(j=0;j<n1;j++)
                        scanf("%d",&p[i][j]);
        printf("Enter elements of 2nd matrix:");
        q=malloc(m2*sizeof(int*));
        for(i=0;i<m2;i++)
                q[i]=malloc(m2*sizeof(int));
        for(i=0;i<m2;i++)
                for(j=0;j<n2;j++)
                        scanf("%d",&q[i][j]);
        printf("product is\n");
        s=malloc(m1*sizeof(int*));
        for(i=0;i<m1;i++)
                s[i]=malloc(n2*sizeof(int));
        for(i=0;i<m1;i++)
        {
                for(j=0;j<n2;j++)
                {
                        sum=0;
                        for(k=0;k<m1;k++)
                        {
                                sum=sum+p[i][k]*q[k][j];
                        }
                        s[i][j]=sum;
                        printf("%d ",s[i][j]);
                }
                printf("\n");
        }
}
}