public class Problem15 {

public static void main(String[] args){

System.out.println("Count: " + iterCount(20));

}

public static long pathCount(int row, int col){

if((row == 19) && (col == 19))

return 1;

if((row < 20) && (col < 20))

return pathCount(row+1, col) + pathCount(row, col+1);

if(row < 20)

return 1 + pathCount(row+1, col);

if(col < 20)

return 1 + pathCount(row, col+1);

return 0;

}

public static long iterCount(int sizeOf){

long[] l = new long[sizeOf+1];

for( int i = 0; i <= sizeOf ; i++)

l[i] = 1L;

int i = 1;

while( i <= sizeOf ){

int j = 1;

while( j < i){

l[j] = l[j] + l[j-1];

j++;

}

l[i] = 2L * l[i-1];

i++;

}

return l[sizeOf];

}

}