Matrix Multiplication

#include<stdio.h>
void main()
{
    int i,j,r1,r2,c1,c2,k,a[100][100],b[100][100],c[100][100];
    goto input;
    input:
    {
        printf("Enter the number of rows and columns of matrix A: ");
        scanf("%d%d",&r1,&c1);
        printf("\nEnter the number of rows and columns of matrix B: ");
        scanf("%d%d",&r2,&c2);
    }
    if(c1!=r2)
    {
        printf("\nThe matrices cannot be multiplied. Try again\n\n");
        goto input;
    }
    printf("\nEnter the elements of matrix A: ");
    for(i=0;i<r1;i++)
    {
        for(j=0;j<c1;j++)
            scanf("%d",&a[i][j]);
    }
    printf("\nEnter the elements of matrix B: ");
    for(i=0;i<r2;i++)
    {
        for(j=0;j<c2;j++)
            scanf("%d",&b[i][j]);
    }
    for(i=0;i<r1;i++)
    {
        for(j=0;j<c2;j++)
        {
            c[i][j]=0;
            for(k=0;k<c1;k++)
                c[i][j]+=a[i][k]*b[k][j];
        }
    }
    printf("\nThe entered matrix A is\n");
    for(i=0;i<r1;i++)
    {
        for(j=0;j<c1;j++)
        {
            printf("%d\t",a[i][j]);
        }
        printf("\n");
    }
    printf("\nThe entered matrix B is\n");
    for(i=0;i<r2;i++)
    {
        for(j=0;j<c2;j++)
        {
            printf("%d\t",b[i][j]);
        }
        printf("\n");
    }
    printf("\nThe product of the matrices A & B i.e C is\n");
    for(i=0;i<r1;i++)
    {
        for(j=0;j<c2;j++)
        {
            printf("%d\t",c[i][j]);
        }
        printf("\n");
    }
}