#include <stdio.h>
#include <vector>
int v, e;
std::vector<int> G[10];
int main( )
{
int v1, v2, i, j;
scanf("%d %d", &v, &e);
for(i=1; i<=e; i++)
{
scanf("%d %d", &v1, &v2);
G[v1].push_back(v2);
}
for(i=1; i<=v; i++)
{
printf("%d: ", i);
for(j=0; j<G[i].size(); j++)
printf("%d ", G[i][j]);
printf("\n");
}
}
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